Looks are an asset but they only open doors, they don’t do anything else. Once through the door it’s everything else, not how you look. What is your concern, specifically? be the best you that you can be. Do the things that interest you and enjoy them. Low self esteem is mostly a problem because if you judge yourself people think you are judging them. Try to give yourself the same consideration you would give a friend, you are a person too, there’s no point in holding yourself to some impossible standard.

I’d say also realize you will make mistakes. Don’t expect every guy to be a perfect match. As you get experience you will feel more comfortable.