If I could go to any regular season game, anywhere, in 2025, I'd pick opening day at Yankee Stadium.
I could see that being a big problem with ticket availability though lol. Opening day is a hard ask. What about the 2nd or 3rd game? Opening weekend would be a fun time and Yankee Stadium is tough to beat IMO.
EDIT: Ah, 90 days. Well given that I'd just pick a city you'd like to visit. Some that jump out to me are San Diego, LAD, Seattle, Miami. Maybe Philly or Arizona. The Mets might be interesting given some of the fireworks between these two teams last season.