Should I heed my significant other's best friend's warning about him? (I'm 21, female; he's 22, male)

I've been seeing this guy for about a month, and he's incredibly sweet and chivalrous. He pays for all our meals and always invites me out. I've met his friends, and we all get along well. However, he’s not the type I usually go for—I tend to like video games and nerdy interests while he fits more of a "typical guy" mold (I’m not sure how else to put it). I understand that relationships don't have to be built on the same interests, but I do wish we had more common ground to relate on. He has a pretty poor memory due to the epilepsy medication he's on. There was one instance where I was telling him about a game I loved as a kid and how they made a show out of it, which I wanted to watch with him. A week later, he mentioned that a friend suggested a show to him, and he ended up subscribing to a service to watch it. I brought up that I had just told him about that, and he genuinely didn’t remember. It made me feel a bit overlooked, like my personal interest wasn’t enough to catch his attention, even though maybe I'm overreacting. Additionally, there’s the physical aspect of our relationship. To be straightforward, he is transgender, and I’ve never been in a relationship with anyone transgender before. I’m a bit nervous and want to give him the space to initiate anything. One night, we had a few drinks, and his friend pointed out that he hadn’t even kissed me yet. He admitted he wanted to but was unsure how to go about it, and then he kissed me. At some point, he asked me to be his girlfriend. Afterward, he got quite drunk, and I helped him home. He was really affectionate and possessive, which I liked. I find myself spending the night with him frequently, but nothing physical has gone beyond cuddling and gentle kisses on the cheek and forehead. He mentioned that he and his friends wanted to visit another friend a few hours away for New Year's, and he invited me. I took off work for it, but then he messaged me today about his friend wanting to leave two days earlier, which I couldn’t manage. I told him to enjoy the trip with his friends, and then he mentioned he didn’t really want to go anyway. Then, his best friend reached out to me. He said he heard I couldn’t make it and was unsure if there was any misunderstanding between me and this guy. He offered that he and the other friends are there for me if things go south. Then he said, "Out of respect for you, if you want a serious relationship, you won't find it with him for various reasons that have nothing to do with you but everything to do with him." He insisted he wouldn't let his best friend hurt me, adding that he had his reasons but wouldn’t disclose them. He concluded by urging me to distance myself from the situation and not to bring it up with this guy. I’m completely at a loss here, and I don't have anyone to talk to. Should I consider ending things with him?