Hey there. First - at the recreational club level, nobody (and I mean nobody) gives a rat's --- about transgender status as relates to cycling, per se. The discrimination you'll find as a transgender cyclist will be the same discrimination you get from living your daily life. However, and second - transgender status will impact you IF you actually decide to become a card carrying, CATegorical competitive cyclist (I assume you're in the USA, so the US Cycling Association, in addition to the state association). Unless you're post-op and have been on MTF HRT for years with natal female hormone levels (within the degrees of natural biologic variation) - you'll find it very difficult to register as a female for the sanctioned races. And to be clear, I'm referring to CAT4-1 (women)/CAT5-1 (men) sanctioned racing, not alleycat racing. Recreational/charity rides - nobody cares. Foremost on most cyclist's minds will be' is s/he a sketchy rider'...the intrinsic male biologic advantage (and yes...there is one...absolutely there is one) will only come into play on the competitive, sanctioned USAC racing side.
In terms of finding a club - it varies. Ask your LBS for local clubs. Not all are the same, either in temperment, tolerance, or goals. Some clubs are strictly racing clubs (competitive cyclists training together) - friendship and acceptance will come through your racing results; others are recreational and/or fitness clubs (cyclists who ride together for fun, comraderie, cardiovascular fitness, etc). The likelihood of you being accepted as a transgender cyclist will be the same likelihood as you being accepted as a transgender individual in your everyday life.
And as for your mph - that would be a good fitness base (esp. if you have extensive mountain, dirt, and 'cross experience) though it means absolutely nothing in competitive cycling. Competition is all about surging, going slow, surging, tactics, etc. Recreationally averaging 18-22 mph is not the same as averaging 25-27 mph while climbing several iterations of Mt. Ventoux over a 3-week period.
I've done a few crits, RRs, and ITTs...the safety pins, however, have been closed for years. Keep us updated/feel free to ask more questions. Also, you may consider posting this question to a cycling website/forum, since you would have the input of entire cycling communities (I've found the response to MTF is mixed in general, but gets especially heated in regards to sanctioned competition), and not just a few of the members on this site. Good luck, and keep the rubber side down.
