I do not live in America, so i can't really reccomend any dance schools round your area lol. I do tap and startted when i was abou 11. At first, I was in the same situation as you. I didn't know a thing about tap. I had never even been interested in dance in my life before. However i joined my friend's dance school, and it is where I still am 2 years later!
When tap dancing, you need good patience. Somemoves can take a while to get, and it helps if you are quite co-ordinated, so you can use your arms whilst tapping. As you get more experienced at tap, the moves will become harder, so you will need to practise. The good thing about tap is it is a laugh. A way of telling whether you have a move right is by listening to it. Sometimes if you get it wrong, you get some really cool sounds which just makes you laugh!
I don't think you are too old to start tap. Anyone can learn it, whether you want to do it just for fun or to become proffesional. Just remember no to listen to what anyone tells you about being too old, and just do what you want to do.
Have fun Tapping, and i hope this helped.