Check wheel bearing to make sure your wheels are turning freely, check your chain to make sure it is still usable for racing. Check your engine compression and document the PSI so you'll have a baseline on what the engine health is like. Check your brake pads to make sure it is ok and flush out the old brake fluid and install new fluid. Check and clean your air filter and check and see if your spark plug color is with in reason for a healthy engine.
Good Luck and Ride it like you stole it.