I got into my first car accident today and I feel horrible?

This is a pretty normal feeling. The good part is no one was hurt and cars can be fixed. You feel bad because you were trying to do the right thing, and ended up having an accident anyway. Don't be too hard on yourself. These things happen. Next time, just remember to look all around the car, be a bit more alert and you will be fine. As you drive more, you will get better at it.