2000 Chevy Cavalier sitting car

Based on the information you provided. Follow these steps:

1) If its been sitting for two years doing nothing, make sure your car is fueled and its battery is charged.
2) open the car door, get in, close door, and fasten seat belt.
3) Place key in the ingnition and turn 3/4's a turn.
4) congradulations, you did it, you started your car. Now go get an oil change and some fresh gas.

Hehe
Now on a more serious note :) if your car has actual mechanical issues and wont start, I suggested you describe them in as much detail as possible and many people here will be happy to give you trouble shooting tips.