Welcome to the forum. I'd suggest trying to get the service history if possible, but if not I would change all the fluids including the diffs (I'm guessing it's 4x4 by the rr diff lock), engine oil, tranny, and coolant. Test the battery, change the plugs/wires (use only NGK or Denso), grease the driveshaft. If you want to get crazy with it, clean the throttle body, IAC and MAF (search if you don't know what they are - there's lots of talk about these and how to clean em). I would go around the engine bay and check all the hoses, and the electrical connections and wiring too.

Congrats and I hope you get many years of driving out of her!