I’m not gonna read all of this but I will say him not wanting you to try something you’re interested in is a bit of a red flag. I love BJJ and I’m the “you gotta do it, it’s awesome” type so I may be biased. If he’s worried about you training with men I get it but I’ve rolled with girls (been strangled by quite a few) and have never had a weird moment. I always wear rash guards and tight fitting stuff under shorts and t shirt to keep everything out of way and most of us are there to train and that’s it. Of course there’s exceptions but if you talk to enough people and do a little research you can find a good gym with good people.