Pull front bumper forward after impact

If only the bumper is bent, unbolt it and replace it. You'll find plenty of them in the salvage yards. Take the mounting brackets with the replacement bumper as they are likely to be bent too. Those brackets are designed to bend to absorb some of the impact.

I've also chained a bent bumper to a tree, then used that to pull the bumper. You have to be careful when doing that as with too much speed and too much of a running start, you can pull the bumper too far, or even tear it off.

It is very unlikely there is frame or structural damage from such a low speed, but if there is, that requires a trip to the body shop. They can pull the frame straight very precisely.

Be careful when working around the shock-absorbing bumper mounts, if you have them. Those can stick in the compressed position, then suddenly release just when you have your fingers in there.