I will think of the children
Nobody except Lee Elia should use a baseball game as an excuse to turn into a profanity spouting lunatic, granted this isn’t church, either. The appropriate thing to do is quickly scan the area when you sit down to see how many youngsters are within earshot, and then tailor the tenor of your conversation accordingly.
Also, if you catch a foul ball, giving it to a kid isn’t required, but it is the classier move. Catching it is the cool part anyway. Snap a quick photo if you must and pass it along to someone who’ll be way more excited. This only applies to legitimately caught foul balls -- if you’re running over kids to try to snag one you’re a monster and forking the thing over is the LEAST you can do.
I will update my wardrobe
It’s a big season, and your attire should reflect that. What’s that? You have a vintage and meticulously cared for 1984 Ryne Sandberg-tee? No worries, that’s fantastic. If you’re stepping out in a Nomar Garciaparra shirsey, however, it might be time for new threads.