[Pelican]

Knowing that you are new to baseball as well as to OOTP, I would think it’s fine to start with MLB only. You can always add minor leagues, at least in the off-season, or when setting up a new sim. For sure, minor leagues add realism, but for you this would be a whole new skill set of player evaluation and development, drafts, promotions, training. Fascinating; but better to learn the MLB basics first. Unless, as I suggested in another post, you want to set up a season to simply monitor the gameplay using default settings. Just as this would allow you to watch games play out and field managers making decisions, adding AAA and AA would allow you to learn how an organization functions, how a general manager developes talent - all merely by watching what happens on a day-by-day basis.