Mostly I choose gender based on how good they look. If males look brutish and carrot-y (no offense to Carrot Ironfounderdsson) or soldier-like, I choose female. If women look like drawn by Rob Liefeld, I choose men.
Though I do have a preference to a ginger short-haired woman (elf if fantasy) if I can't decide on what I want to make.
NOT any of the movies. Avoid them until you know you enjoy the tvseries. And I believe you should start at Strange New Worlds. A recent series that quickly gets itself into what we enjoy about Star Trek.
You COULD see if you enjoy Discovery too. I think its a bit too far from what makes Star Trek fun (team work and optimism), and it too quickly delves into mirror world stuff, which you really should have more context about. Picard is a bit too much dependent on knowing stuff from The Next Generation. Lower Decks is making fun of Star Trek lore. And Enterprise and anything older is good and watchable if you enjoyed Strange New Worlds. They all have a bit slow first season though. The Original Series is too old to be watchable for me.