Free vehicles often have problems.
MANY of these Models have Aluminum Engines and sometimes when the Timing Belt/Chain snaps, the top end (Lifters, Valves [Head?]) is destroyed.
WE have a '93 sunbird with the 2.0 L4 and in the late 90s, my wife was driving when the Timing Belt snapped and the engine stopped. The Mechanic stated it was a good thing the Top End wasn't harmed which was rather unusual for these Engines.
Best bet to determine what is involved is to remove the Valve/Cam cover and inspect. If there are ANY obvious metal bits about, you're looking at a probable Top End replacement (Valves, Lifters, possibly the Head).
IF any obvious metal bits are discovered, one should pull the Head and observe the Pistons. ANY damaged Piston, rebuild/replace Engine.
It's a bummer to get a car with questionable Engine conditions.
I HOPE FOR YOU IT IS MINOR!!