As another mention, you can add an additional lineup under squads. Since you’re new, you may not have a bunch of Yankee players yet or a bunch of great Yankees players yet, but that’s ok.

I don’t know what modes you’ve played, but conquest is good. That being said, if you haven’t played conquest yet because of how new you are, just go to single player mode and select play vs cpu.

From there, again not knowing your experience, the easiest is select the Colorado Rockies at the team you want to play and select your team as the away team so you play in Coors field. I only say that because depending on how new you are, you may not have unlocked Coors field yet to play another easier team with Coors field as your home field.