2002 Chevy Cavalier Do I need a tune-up?

I have a 2002 Chevy Cavalier and it just hit 100,000 miles. At about 98,000 miles I started getting problems. When my car is not running and my foot is on the brakes, the engine sounds like it's accelerating and still wants to move, and when I'm about to back up after my car has just been turned on, I have to accelerate quickly or else the car will shut off. When I'm in park for too long it still jerks and sometimes shuts off. Also, when the car is in park or at a standstill I can hear like a knocking noise and the car sounding as if it's trying to accelerate. Are these the signs that I need a tune-up or what else could it possibly be? Also, my engine light stays on and my 'TRAC OFF' light goes on and off.