First, remove the hose and box that bolt from the throttle body to the area near the radiator cap. Second remove the box below that you can now see, Third open air filter box and change filter.
Loosen the hose clamps on each end of the big square air box and remove it. Then you can release the clamps on the air cleaner box, remove the lid, and remove the filter.
A 2000 Chevy Cavalier does not have a cabin air filter. These standard vehicles came with an engine air filter located under the hood of the vehicle, in the air box.