You've already made the first step. You've come to the right place.
I'd start with the basic tune up stuff. Oil change, plugs, wires, cap and rotor. Maybe belts. Check the air cleaner and change the fuel filter. Then see how it does. With out knowing when the timing belt was changed, that should be considered too. Tuneup stuff will give you a good idea on the power issue if any. Maybe run some fuel system cleaner through too. Uh- yeah. That's what I would do.
Welcome aboard!!

-Adam