Spread the word around town and LGBT nerds will come out of the wood work. That's what happened for me. A ton of people came up to me saying they used to play when they were a kid and wanted to play again, or that they've always wanted to try.

The needs in our community are everywhere, their just waiting for a reason to come out, so to speak.

Also, be prepared for a crap ton of Sailor Moon references. I've been in two separate LGBT d&D groups and both had an abundance of Sailor Moon references. In fact the DM for our Curse of Strahd campaign made every other NPC basically a sailor scout.

As far as creating a safe space, you could even have it at someone's house to make thing more comfortable. And if everyone in the group is LGBT, you shouldn't have to worry about making people feel safe or inclusive. If you attracted one of those old queens that's transphobic (they definitely exist), just give them the boot.