Tailgating – first time

Hey all! I plan on going to the Texans vs Bears 9/15 Night game for tailgating only. Got invited by some friends but this will be my first time doing so. Got some questions hopefully I can get some answers:

1.) I plan on driving up there and parking in one of the lots, will just purchasing a parking pass be enough?

2.) I will have about 4 other people with me, aside from purchasing the parking pass, is there anything else we will need, or will we just be able to roam around the parking lot and mingle without having to purchase anything entry wise?

3.) Are we able to bring our own liquor into the parking lot? Do they search vehicles or is it ok?

Sorry for the newbie questions, just trying to prepare myself best as possible. Any additional tips/suggestions are definitely welcome as well.