Riding Amtrak in a few days?

Hey guys, I am on vacation right now and in a few days I will be riding my first Amtrak on my way to the airport. The station I am departing from has no checked luggage and my suitcase is 2 inches longer than the checked luggage allowed size. However, I called Amtrak and they said it shouldn't be a problem. I will be taking a backpack, camera case, and suitcase that is 30 inches rather than 28. Can someone tell me if this will all work and what else I need to know about traveling on the Amtrak? Thanks.