What a great 50th Birthday present to give yourself!

Welcome, Susan! I'm glad you're friends with a habitual Greeter: you will have lots of reminders about 1-ply and MOOP, and less cause to doubt that you are welcome in Black Rock City at any given time. Lots of virgins are nervous about being welcome . . . but welcome you are.
Especially if you're nice to the potties and the environment.
The 9 o'clock side of the city is considered the "Red Light District" (generally from 7 o'clock to 9'o'clock-ish) but the whole city is pretty relaxed about things (I really didn't know there was a difference for a long time, but Kidsville is on the other side of the city, so there IS a bit of a difference, I guess).
You will find lots of camps that suit your interests; I might suggest Retrofrolic and Suspended Animation camp--amid the many. (Google them, or google their names with the keyword eplaya added). These--and many others of interest to you--will also be listed in the What/When/Where guide you receive at Greeters, and will probably have a listing under "Theme Camps" on the main site and in the 2012 Theme Camps forum in a few months. Stick around and you'll see . . . there are new camps every year, too.
And Yoga will be, well . . . everywhere!