We need more info to know for sure. Where is it pushed out, how and how far? If it is the base of the stud wall that you pushed out (by hitting it with your car?) then you need to "persuade" it back into place by tacking a 2x4 or 6 on the outside, parallel with the bottom plate, and wacking it good with a large sledgehammer to get it back in place. Once you get it back in place then you need to re-attach it. This could be trickier. You will need a very large concrete anchor, a hammer drill to make sure that the wall is fastened to the masonary. If you had a cinder block foundation wall, or if the poured concrete was damaged then the structural repair may need more extensive work. It is not enough to just push the wall back in place, you need to make sure it is firmly re-attached to the foundation. For REALLY quick drywall repair you can use fiberglass mesh tape and plaster of paris. Be cautioned, the plaster of paris sets up in seconds and is rock hard, so any high spots will cause you grief if you need to sand them down.