Well I would start with checking and replacing the air filter.
I just made that guide real quick since I couldn't find a good guide for changing air filters.
Changing your spark plugs
would also be a good Idea if they look original.
You could also try using sea foam, I would put a can in your gas tank when you fill it up, then get another can to do this procedure
when the tank is almost empty.
Those are places to start, with no guarantees, but they are basic maintenance things that should be done to the car if they haven't been done already and they are fairly easy to do, a ~100 peice tool set from walmart will have everything you need in it for less than $40.