I agree with everybody here. While there are some things about your composition or exposure in some shots to be worked on, you took some really nice photos for someone starting out and for only $100.
I paid 3 times as much as your agreed upon price for my wedding photographer, and I wish she had gotten the types of shots you had. She was good, don’t misunderstand me, but she wasn’t a wedding photog; rather, she was a commercial product photographer and a friend, so she did my husband and I a favor. It just didn’t have a lot of flair as a wedding photog would have for their chosen line of work. But I did pay her the agreed price – and even tipped her extra for her troubles. It’s just the right thing to do.
You did good. Keep working on it and chalk up your loss as an experience to learn from. And definitely: be wary of working for family or friends, because they’ll expect, nay demand, you give them your time for cheap.
In the meantime, you could soothe your pains by enjoying a site like Clients from Hell or the like. You’re not alone.