how to dance

Have a few drinks or smoke some pot,
Everyone has rhythm when they do either of those things.
You need to relax, and not be self conscious, just go with the flow, but being relaxed does help.
When a good song you like comes on, go and dance with your girlfriends
You need to be ready because it will happen that a hunky guy will approach you and ask you to dance.
If you enjoy music, and tap your feet to the rhythm then you can dance, honest
Seek out a dance class, that might help.

Well I'm 25 and I don't go to bars. So, good job! When I used to dance at dances I would just go crazy, but this is not the best way to 'dance like everyone else is dancing'. And people will probably look at you funny, but ignoring them is a part of the high you get from doing it. However it is a way to just let yourself go. I found that I love dancing and really get into the rhythms. Beat just feels great, and I'd like to go to a rave, but haven't yet. It's hard for me to dance as a pair, but have had a fun dancing partner in the past. I tend to know what I want to do and don't look at the others for directions...that matter anyway...?
But if you want to have fun dancing at a bar I wouldn't know what to tell you. Just get into it, or have a good time, or something!