If the trainer hasn't been run in a few years, take the tank out and clean it out, then replace the stopper and all the fuel lines. Get new o-rings for the carburetor and both needle valves. Check all the screws throughout the airplane for tightness and install a battery and make sure all the servos move smoothly and don't bind. While you're at it, get your control throws right per the manual. Check all of the control horns and give them a good yank to make sure they aren't cracked or deteriorated. Make sure your landing gear block is solid and the wing attachment dowels aren't cracked or coming loose. Check anything else you can think of. This is the stuff you can do by yourself and maybe catch a problem that would have cost you a training day.
For fuel, any 5% airplane glow fuel will run the Super Tigre just fine. Omega or Cool Power are the two most common where I live, but any of them will work.