i think its my clutch but im not sure.
when my car is off i can shift it without the clutch in just fine, but when i start the car it wont shift at all. clutch in or out and you have to force it into gear (grinding) but once its in gear i can use the clutch to slip it into gear. what should be the first thing i check out?

 

I'd pull the tranny and inspect the clutch. Pressure plate could be screwed up too.