Al has already written the definitive BCB guide to 2019 Cubs promotional items however this year there is a second set of giveaways with its own set of rules. It’s sort of like the secret menu at In-N-Out, but for baseball swag.
To take advantage of Cubs Community Nights (and they are calling them “nights” even though some of them are day games) you need to buy your ticket online through the Cubs Community Night link. That ticket will entitle you to pick up the item associated with your ticket in Gallagher Way before the game.