I did the local adult tap class before I got PG this year and it was fantastic! I have done it before, though as a child, so found it easy to pick up. It should be the basics if it is a true adult tap class, but you quickly progress to more impressive looking stuff. I'd go along and have a go. You've got nothing to loose! I met some really nice people, too, and we'd have a good chat in the break and afterwards! I'm looking forward to going back once DS goes longer between feeds (DS is now 6 weeks old!).
Don't bother buying tap shoes until you know you'll be going back, just wear comfortable shoes and clothing that's easy to move in.
Thanks, Ladyem. I'm doing visits to secondary schools' open evenings for the next couple of weeks, but once that's over, i think i might go. DD1 is going (different time, obviously) so it might be fun to practice together.