Hi I applaud you by sticking up your middle finger to expensive repair shops and dealers that charge obnoxious fees for easy to do work.
Since you have no formal training and or experience.
Lets get you started in the right direction, You will need tools, shop equipment and data.
Not just for this brake job but for any repairs you decide to tackle on your own.
The least expensive best source for the Home Mechanic to buy tools is Harbor Freight.
but if you can afford Snap on Mac or even craftsman get the better brands.
If you are on a tight budget buy basic hand and shop tools from Harbor freight.
Use Napa Autozone and other parts stores for their tool loaner program,
you will buy a used tool like one you may need to spin rear calipers back in place to do rear brakes on most but not all rear disk brakes.
Once your done return it for a refund.
At harbor freight you will find Floor jacks and jack stands, and all the hand tools you need to beat the system doing it yourself inexpensively.
To find out exactly what tools you would need and all the procedures you be doing, you will need a factory service manual which is very expensive new at GM, possibly less if you find a used one on eBay.
for brake jobs I keep on hand Allen sockets metric and SAE, Torx sockets, and basic 6 point sockets. a long flex head ratchet, a c clamp vise grip for pushing the piston back but they make tools for that job.
rear disk brakes sometimes need to be spun back in while pushing and normally requires a special tool for this job, HF has them or they can be obtained through a tool loaner program through Napa, explained later in this post.
The least expensive option for data and procedures is Alldata diy and mitchell 1 DIY
Mitchell is the cheaper of the two.
Since your brakes are wearing uneven, there may be a problem with the caliper slides , servicing these properly is key to properly working brakes.
All of this is covered in the manual.
Just to have front brake pads done at the dealer will cost you north of 300 dollars.
So the little investment on a manual or subscription will pay for itself the first use.
Start by getting a manual or subscription go to the brake section and read the entire section on brakes and servicing your brakes.
read it twice if necessary. then check all the factory service bulletins that are related to the brakes.
Many times a manufacture will find that a certain brake pad or caliper slide or who knows what has a factory deficiency that is cured with a upgraded part or procedure.
By skipping this step your setting yourself up for future premature brake failures or quirks like squeaks, rattles vibrations, pulsations low brake pedal etc.
All of which could be avoided by reading the TSBs
when you buy parts, buy good parts!!! Your saving money on labor and taking the time to do it yourself, so do not set yourself up for disappointment or failure spend the money once, purchase good parts.
When it comes to brakes I prefer factory parts but those can get pricey.
I use Napa and get their best quality if I cannot afford the factory parts.
Some people will give you generic help telling you to jack up the car remove the caliper squeeze the caliper piston back into the caliper to make room for the pads.
This may be OK if you have nice clean uncontaminated brake fluid and no garbage built up behind the piston.
But if you have contaminated fluid and rust in the system you will be pushing this garbage back into the system up to the master cylinder and through any anti-lock pumps and manifolds proportioning valves etc that your car may have.
Rule number one a brake system cannot be too clean inside or out ,you or your tools cannot be too clean while working on them, So wear disposable gloves and change them often as needed.
Have a small slop pan to protect the floor while your working.
keep plenty of non flammable brake cleaner and a stiff parts washing brush near by and use eye protection.
At this point you have to decide what type of brake job are you going to do?
Are you just hanging pads and replacing rotors topping off the fluid and hitting the highway?
Or are you addressing each and every part that makes up the braking system?
To answer that question, how many miles does your car have on it?
If you need both front and rear and the front have been replaced before I am guessing your at well over 100K
If so plan on rebuilding or replacing the calipers front and rear and closely inspecting the flexible brake lines. I would also recommend rebuilding and or replacing the master cylinder. and flushing the entire system with new fluid when your done.
rebuilding these parts rather than replacing them will require more time more money in parts.
If you break it down to manageable small projects it can be accomplished over time by putting priorities on the unsafe items first.
Since the front brakes provide the majority of your stopping power I would say that is your best bet.
If you can afford the time and have a second car to make secondary parts runs for the unknown that always comes up when your knee deep into these types of projects. that would be best.
normally when I do brakes and I do not plan on rebuilding the entire system and it has nasty fluid. I would start by jacking up the car and supporting it with jack stands.
Remove all four wheels and get a drain pain under the right rear wheel.
Having plenty new in a sealed bottle of brake fluid of the correct type for your car ready.
I would open the bleeder and remove the master cylinder cover. allowing the brake fluid to gravity bleed until the fluid comes out nice and clean.
Always keep a eye on the brake fluid in the master cylinder not letting it get too low. topping it off when needed.
Once the fluid is clean at the right rear close that bleeder and clean any mess that was made with brake clean.
Move to the left rear and gravity bleed it till the fluid is clear, then the right front then the left front.
When your happy that you have clean fluid at all four corners and at the master cylinder let the fluid drain most of the way out of the master cylinder leaving it about 1/4 full.
This leaves room for when you push the pistons back into the calipers causing the fluid level to come up in the master cylinder. if the level is too high it may push out under the hood making a mess.
Once the brake job is done top off the fluid. but for now just leave it about 1/4 full with the top on the master cylinder.
The do the brake job as per the manual.
This step will help a little by getting some of the trash out.
Millions of mechanics do not do this and you may not need to either I figured it was worth mentioning and you could use your judgement.
Since your on a budget and this is your first time, always do one wheel at a time, when your done with that one wheel pump up the brake pedal and make sure you still have a pedal and it doesn't sink tot he floor board.
If all is well move on to the next wheel.
I say this because of a car I worked on years ago when I first started.
I did brakes all the way around, put the wheel back on, quickly pumped up the brakes topped the fluids off kick the lift out from under the car and started to back the car out of the shop. to find out the pedal pumped up but would slowly leak down like a had a bad master cylinder to deal with.
I had a few other more experienced tech look at my work they felt the pedal and we all agreed the Master cylinder was bad. from pushing the old fluid back through the lines and system.
well I bench bleed the new master installed it gravity bleed and had a hand bleeding the system yet the pedal slowly went to the floor.
So I we all blamed the cheap part my boss provided, I installed a brand new part from ford. same problem.
Turned out in my rush to do the brakes, I looked at my original work to find
the metal tab that kept the pad from moving around and it also kept the caliper in place.
Was rushed on and not put back in place correctly,this metal bar now acted like a spring that would push the piston back into the caliper creating a space between the pad and the piston.
This problem acted like a bad master cylinder and fooled every single tech in the shop.
So take your time, do not rush take pictures if necessary and do one wheel at a time. make sure the brake pedal feels right before you move on to the next wheel. this way if something goes wrong you at least know which wheel your problem is at. I can not stress this enough.