Shooting a Clemson Football Game: My schedule
I've shot a total of 6 Clemson football games so far, which I think qualifies me as experienced. Through trial and error and talking with friends I've developed a schedule that I usually follow for shooting a game.
All of my times are approximate, change them if you do/don't want to take pictures at the Tiger Walk, band amphitheater performance, eat in the press box, etc.
First orient yourself by looking at this map. the East zone is where the Hill is, West is the covered side, Southeast corner is our student section.

2.5 hours before kickoff- Check in, get photography vest, eat some food in the press box (Purple path)
Go to gate 16 on the south side of the stadium. Walk up to any of the event staff or security people, show them your media pass, and say you're a photographer. They'll poke through your bag (I always open the pockets for them so that nothing falls out) and then put a wristband on the bag to denote that it's been searched.
Once you get past them, walk down the ramp and enter the door on the right. Then walk forward a little bit and turn right, halfway down that hallway there should be some guys at a table with some papers. Say hey to them and that you need to check in and get a vest. They'll have you pick a navy blue vest out of a bin and write down your name, vest number, and the group you're with (I usually write photography club). They'll also give you the wifi password if you ask, which is great. Last game it was Cl3m50n T1G3r5 I think.
Now you have your vest and you're all checked in, so continue down that hallway to the official press box. They should have some food and drinks for you. If it's a noon-ish game they'll have breakfast food (the scones are great), otherwise it will be lunch/dinner/snack food. Eat here, chill in the AC/heat for a bit, relax and maybe talk to some other photographers.
2 hours before kickoff - Go to media room, place bag down (Red path)
The easiest way to leave the press box is to walk out the same way you came in. Yes, leave through gate 16. It feels weird to leave the stadium, but this is the easiest way. Then walk down the hill toward the Oculus and go in gate 10 or 12. They might look through your bag again, might not. The media room is the red star on the map above. There's a glass door that says "Sports Medicine", and just inside of that is the media room where your gear should be safe. There should be other photographers or gear already in there so you'll know you're in the right place. If you can't find it just ask someone else with a big camera or anyone in the green event staff shirts.

1 hour 45 minutes before kickoff - Whatever you want!
2ish hours before a game you can basically do whatever you want on the field. The field is mostly empty because the players aren't warming up yet and just a few people are setting things up. If you want pictures of you on the football field, now is the time to take them. Sometimes I'll go up to the top of the stands to take wide angle shots of the stadium.

(Optional) 1 hour 30 minutes before kickoff - band performance in the amphitheater
The band always performs a small show in by the library 90 minutes before kickoff. It's a great opportunity to hear the full power of the band, and a nice activity to go to when there isn't much else happening around the stadium. It's a short hike from the stadium.
45 minutes before kickoff - Wander the field
This is the time I typically use to test my camera settings for the lighting that day, talk to photography friends on the field, and find a few friends in the stands. It's still pretty chill, but you can feel the excitement growing.