We are all star wars geek to some extent. Some more than others.
Even within the 501st there are different levels of interest. So no-one would feel out of place there, even without an outfit.
Though if you do fancy joining up.
Beware!!!! once you start on that road with one costume you
will want more

I've been turned to the darkside and have 4 now. Blimey! it ain't cheap!
....
Hi Invader
thought I'd say hi from the UK Garrison, the UK section of the 501st. Keep an eye out for names with [UKG] prefixes. Most of us have the game now. See you all online.
Dom