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.
25 minutes before kickoff - go to the field goal post by the hill
Around 25 minutes before kickoff is when I wander over toward the hill. When the players run down the hill all the photographers have to crowd around the goal post so we don't get run over. I typically stand in the back and shoot over someone's head because I'm tall, but you can also crouch in front. I don't have a great picture showing where I stand, but the picture above should give you a good idea of where it is.
Once activities start on the top of the hill you have to stay there until the pregame activities are over.
Kickoff through halftime - wherever I'm allowed to be
You can only take pictures where the yellow blocks are in the picture above. There should be a white line and a yellow line around the field, stay behind that. Typically people will tell you if you mess up. You can walk behind the players to move from one side or the other, but do not take pictures from behind the players' bench area. I've been told that's a great way to lose your media pass. So don't do it. You can take pictures on the field, but typically it's frowned upon to take pictures when they're chilling on the bench. If Dabo walks onto the field a yard or two and screams at people then it's fine to take pictures of him.
As for positioning throughout the game - it's good to be on the half of the field that our team is running towards. This puts you in position to capture any long pass catches or any touchdowns. I enjoy being around the hill and student section so I can get fan reactions when good/bad things happen, and to take pictures of my friends.
I recommend taking pictures of friends earlier in the game rather than later, because after halftime a lot of friends will leave if it's a blowout game or it's really hot or cold.
Halftime - In front of the band
It's super fun to be right in front of the band as they perform at halftime. I think they alternate the side they play to each home game, just ask any band member which way they're facing that day and they'll tell you. I just take pictures of the dancers during this time, but you'll probably want to take pictures of the whole band. You can go in the players area for this, but don't go out onto the field. When the show ends the band will walk towards you very quickly, move and try not to get run over.
Third quarter - snack time!
Once halftime ends I usually put my camera in the media room and hike up to the press box to grab a snack. Sometimes they have good food and sometimes they're running low, but it's always good. The also usually have ice cream if it's hot outside or hot chocolate if it's cold outside. I try to only spend 20 minutes total on this break, but it takes 5 minutes or so to walk each way.
Fourth quarter - Push through, go wherever. Lights if it's a night game
If it's a night game you definitely want to be back on the field by the time 4th quarter starts, because that's when everyone in the stadium turns on their phone flashlights and it looks awesome. It doesn't really matter where you are for this, but near the student section is always nice.
You'll probably be getting tired of taking pictures at this point, but push through. You can do it. Take this time to be a little more selective and patient with your pictures because you've probably already taken a lot of great shots throughout the game. If it's a blowout the crowd might be thinning out, so it's a little too late to take crowd pictures at this point.
If it's a really exciting game you might want to be near the student sections to get reactions from them
When the clock hits 00:00 - Rush the field, fireworks if it's a night game
Since you're already on the field as a photographer, you can get pretty close to the middle of the mosh pit that happens after every win. I usually hang back a little bit and stay on the side near the media room so that I can leave after the alma-mater without too much issue. However, if you want to be in the middle of everything, this is your chance. Just protect your camera and don't fall and everything will be okay.
If it's a night game and we win, there might be fireworks that go off by the Oculus. Those make for cool pictures.