First off I'm sorry you got downvoted into the ground. You seem like you have good intentions but you're just a little naive on trans issues.

So you have a preference for the female form and penises. That's cool, it's not a common preference but there's nothing wrong with it. The problem is that you're going to have a very very hard time finding a woman who has a penis and wants to keep it and is comfortable with it. It goes without saying that most women don't have penises and you can't exactly screen people because asking someone about their genitals is almost never okay. I would say just be persistent. It might take many years to find that special someone but I bet it'll be worth it in the end. Trans women don't generally congregate - we're just normal women.

I'll briefly mention that it's not okay to go to LGBT social groups to hit on women. You wouldn't hit on women at your kid's soccer game right? It's the same sort of setting - purely social. You're there to have some fun and meet new people but you're not there to start a sexual relationship.

Also I'll make an obligatory note that it's never ever EVER okay to fetishize a trans woman's (or a trans man's (or anyone's for that matter)) genitals. Most people appreciate it when you fall in love with them rather than their genitals. It's important to make a distinction between a preference and a fetish. Everybody has a preference (except for some ace people ;). Most lesbians probably have a preference for the female form and vaginas (not all of them though, for example I don't particularly care what genitals someone has so long as they're feminine.) Most straight women probably have a preference for the male form and penises etc. A preference becomes a fetish when rather than seeing a whole person you just focus on one part and that's all you're attracted to. Attraction like this isn't very healthy when you want a LTR and your partner can end out feeling used :( Fall in love with the whole person. Fall in love with her laugh, the way she smiles, the way she makes you feel when she tells you she loves you.

So good luck. Just keep learning and listening and you'll get there in the end. I would say don't be deterred if you do something that makes a trans person angry. We put up with a lot of shit and sometimes it gets overwhelming. Instead, just try to remember not to do that thing again. Maybe if you were confused ask what you did wrong so you know for next time. I can't speak for everyone but personally I love it when people care and want to learn when they've accidentally hurt me.

I hope this has been helpful.