What Do I Wear?
You have two clothing options when you first begin training.
Option 1
Loose fitting clothing (example sweats and a t-shirt) please do not wear shorts, halter tops, shelve less shirts, jeans, etc. 
Option 2 (Preferred)
A white single weave judo or aikido gi and a white belt.  If you need assistance determining what size you wear please feel free to ask.  There are many places you can purchase a gi if you choose this option.  Most beginner grade gi run between $40-$70 depending on your size.  At the bottom I have listed some commonly known places that you can purchase uniforms from or you can research on your own and find another vendor to buy from. 
***Just a little advice, when you are first starting it might not be wise to spend a lot of money on an expensive gi.  After you train awhile you discover what kind/brand of gi suites you best. 
Well-Know Places that sell uniforms
www.bujindesign.com
www.ebogu.com SEE WEB RESOURCES PAGE
www.tozando.com
www.budostuff.com
All Martial Arts Supplies
4025 W.   Charleston Blvd.
Las Vegas, NV89102
702-878-2883