There's a chance it might cost you upwards of $150-200 to spot repair damaged garage door panel. If it happens to be an in-production model, they probably will be able to repair or replace the entire panel (if needed) for $250-400.
It is indeed possible to replace just a single panel on a garage door. However, if multiple panels require replacement, it may be more cost-effective to replace the entire garage door.
If it's higher than four feet off the ground, or lower than three feet, you'll know it needs to be realigned. Use a ladder as a brace to keep the door safely open while you're working on it. This also takes the pressure off the springs so you can inspect them for rust and warping.