If you are gay or gay friendly, and you respect the views of others (while perhaps disagreeing with them), and you believe that clicking your heels will, indeed, help you find your way home - then welcome.
Judy Garland played the part of Dorothy in The Wizard of Oz and was very gay friendly.
She used to hang out in the gay piano bar in Boston and at a time when it was not "safe" to ask about someone's sexuality, the code was to ask if they knew Dorothy, or if they were a "friend of Dorothy's". If they answered yes, then you were pretty sure they were gay.
If you go on some cruise ships (like the Holland America Line) they have a "Friends of Dorothy" meeting, also may have a "Friends of Bill" which refers to the first name of the founder of AA.
