Echoing what's already been said because it's true- temps this week are above seasonal averages, mid-afternoon kick-off, it's gonna be warm with intense sun. Hydrate well in the morning and wear a hat, sunscreen, and sunglasses.
Unlike some schools, who have stadiums built adjacent to campus with parking lots surrounding the field, CU's stadium remains in the same place it was built in 1924. The net result is that it is largely in the middle of the campus, surrounded by various buildings. Most available parking lots on campus turn into tailgating areas, the closer to the stadium, the more frivolity and fun.
For example, I usually park tailgate in lot 470 near the Law School, then proceed up to the IPF as kickoff gets closer. It's bit of a trek to the stadium, but it's fun to feel the intensity build the closer you get. Ralphie is usually out in the alumni tailgate area a while before the game.
The new indoor practice facility and adjacent practice field are fun to visit, and you can buy beer in the inside... I think you can bring your own onto the practice field, but no glass. Someone can maybe confirm that. The Balch field house, to the west of the stadium, is the old basketball gym and is also a just a horde of people drinking before the game. They usually have another game playing on the screen in there, and you can buy beer. Both Balch and the IPF are good ways to get out of the sun.
Don't miss Pearl Street, including the "stampede" the night before, where the players and band walk down the street. Usually starts at 7pm at the Boulder County Courthouse. Eldorado Canyon State Park and the Peak-to-Peak highways are easy ways to get a Colorado outdoors "feel" without venturing too far.
You'll have fun.