Here's the thing about dances; if you aren't planning on actually dancing, don't go to a dance. Because, guess what: You wont have any fun. Just don't give a shit what people think, kick up your boots, and you may actually enjoy yourself. Trust me on this one.
And this advice is as much to me as anyone else, because sometimes I forget my own mantra. I promised myself I wouldn't think to much, and I have been. About how people are smarter and more physically fit and more attractive than I am. I forgot that these things don't really matter.
Happiness is the only thing that matters. I remembered that sometime last night.
I don't think you need to dance well. Just as long as you are brave enough to dance, I think it will be ok.