Some little things you need to know:
The "sticks" (also called "the chain").
On the sidelines are the sticks. They are about six-feet tall and each is held by a man. One is placed where the ball is downed at a first down. At the top of this one they will display which down it is. The other stick is ten yards away. There is a ten-yard-long chain between them. Sometimes this is used to measure for a first down. They actually bring the sticks and chain onto the field. On first downs you'll hear the announcer say (sometimes) "They moved the sticks" or "they moved the chain."
No, these aren't guys who beam down with Captain Kirk and fail to return to the ship. Every player has four years of college "eligibility." That means they can play college ball for four years and only four years. So, if a team wants to keep a player but not play the player (give him a year to get better), they can "red shirt" him. He doesn't play and he keeps his four years of eligibility. It used to be they couldn't play in any games. But in 2018, that was changed to where they can play in up to four games and still be considered a red shirt. I think this is a good change.
Because of this you'll hear the expression "red shirt freshman" for a player that was red-shirted for a year. He's probably academically a sophomore, but in football he's a freshman. You'll also hear "true freshman" for a player that is right out of high school and playing in the game.
Football is one of the few games I know of where crowd noise is a factor (basketball is, too). When the visiting team has the ball, the crowd will try to make a lot of noise to disorient the players. Perhaps they won't hear the quarterback's signals and move late. Or they might move early, earning a "false start" penalty. The higher the down, the more noise the crowd will make. This is true in both college and pro football. Century Link Field, where the Seahawks play, is known for being the loudest stadium in the NFL. Husky Stadium, where the University of Washington Huskies play, is also known for being loud.
Sometimes a visiting team can "take the crowd out of the game" by playing well and discouraging the fans. But when 50,000 people are screaming at you, it can be unsettling.
The officials are human and they make mistakes. That's why there is replay review. But still, some subjectivity comes in. Was that holding or just aggressive blocking? Was it pass interference or just a good job keeping the ball out of the receiver's hands? And where they place the ball at the end of a play can be subjective. It's supposed to be where the ball is when the player is down. But sometimes it gets moved a few inches in either direction. Sometimes this results in a first down when it should have not been. Or a team doesn't get a first down then they should have. Remember, football is a game of inches.
Each team is given six time outs: three in the first half and three in the second half. This is when they can stop play for a period. How long seems to be about a minute or sometimes only 30 seconds. I don't know what determines that. Time outs stop the clock which toward the end of a game may be a necessary strategy. If a team doesn't use all three of its first-half time outs, it still only gets three for the second half.
"Depth" or "depth chart" is how many players a team has to play at a certain position. The more the better. If you have only a starting quarterback and one back-up quarterback, you don't have much "depth" at the quarterback position. If you have five back-up quarterbacks and they are all pretty good players, you are said to have "good depth" at quarterback. A team with good depth (or a good depth chart) at its key positions can deal with injuries causing players to not be able to play much better than a team without good depth.
College football wouldn't be college football without rivalries. Rivalries are part of what makes college football so fun. A rivalry is when two teams especially dislike each other. And while they want to win every game, beating a rival is especially sweet. Most rivalries are based on geography (Washington/Washington State, Florida/Florida State). Some are based on past actions. The Washington/Oregon rivalry is such a case. It was caused by some boorish actions by, unfortunately, Washington players after a victory and then Oregon being insufferable when they started beating Washington in the early 2000s.
Probably the most famous rivalry is Ohio State and Michigan. I'm not sure what started it.