I take girls to MLB baseball game dates all the time--because I'm a huge fan and have been playing every year since I was 7. Let's be candid, it's a very unique thing to do for women, mainly because most guys these days are living with their parents, busy playing video games, and have no money. The MLB stadium (Coors Field) in my town is right downtown so bars and drinks before and after. All is within walking distance. Even the girls I talk to casually, young ones too, all love to go to the games. I show them a great time and always get laid after.
Bro, no disrespect, but you'd better study up on how baseball works and is played (can't even believe I just typed that for a guy living in the US) and some other info about the teams. You really don't want to come across as the nerdy non-athletic guy who doesn't know crap about sports. MLB is still hugely popular and woven into the fabric of the US culture deeper than any other sport.
It's a golden opportunity for you to teach her about the game and be a leader. It would be a train wreck to go and not know s*it about the game or teams. Kind of reminds me of the guy who walks into the gym locker room, looks at the tv (any major sport being played) and asks "Hey guys, who's playing?" F*uck, huge point deduction off of their man card...you NEVER ask that. But, maybe not in 2021...
And DON'T tell her you were comped the tickets.
Good luck and have fun.