I would start by looking for trainers/barns in horsetrader, and other horse related publications, call up some trainers, talk to them, get some references, see what type of vibe you get with just the basics, and then if you like a place, go by, talk to some of the boarders/students without the trainer right there, and see what they say. Watch a few lessons, hang around for a little bit, and see how the trainer conducts his/herself, and once you find one that clicks, then start taking lessons, or leasing. Honestly as long as you aren't hugely PDAing at shows with your partner I don't think anyone will have serious enough issues with it to "ban" your partner from coming to support you, and if they do, then they don't deserve your interest and money to show at their facility. I personally do not think that being a homosexual is right, but I still believe that as a homosexual you have the right to your own opinions, and should be allowed to have your partner come support you in what you love to do. Just get out there, and talk to some horse people, find out what shows are going on in the area, and go watch, and talk to some of the competitors, that's another great way to get information about trainers, and who's out there, and feel people out. Good luck, I hope that you find a place that is accepting of you for who you are, where you feel comfortable being yourself.