Buy a vehicle without complex mechanicals or electronics. A stick shift, stripped Honda Civic or Toyota Corolla, Mazda Protege/323 would qualify. If you don’t need a backseat, I would pick a Ford Ranger pickup with stick shift. It has rear drive, is easy and cheap to service, and has a good reliability record. In all cases, only buy a vehicle that has been well maintained and has reasonably low mileage for its age. For $3500 avoid anything with automatic, power windows, sliding roof, or other items that can go wrong.
Good luck!