2000 Chevy Cavalier my car shakes

Ok when I start my car it runs good for 10mins.
when its idealing my rpm raises up and down every so often. And when I step on the gas my car seems like it hardly likes to move and when im at a stop light it seems to shake very badly and I have to step on the gas a little just to make it stop shaking and when I come to full complete stop when I put my car in park it just shuts down completely please help with this question befor I spend 1000$'s of dollars on a mechanic.
( o yeah my check engine lights has been on for about 6 or 7 months now)