I have four boys; the oldest just turned 8 and the others are 6, 4, and 2. We have had season tickets for a decade, increasing the number of tickets as needed as the family has grown. This is what works for us:

Any kids under 3-and-a-half years old: we leave them at home with a babysitter or with family because they are really difficult at the games and we end up spending the whole game chasing them around.
Kids 4-5 years old stay engaged with the game off and on for the first half.
6-year-olds will watch the first half before getting bored.
7 years old or older can watch the whole game.

What we do is bring a few small toys (cars or trains) for the 4 year old to play with when not watching the game. We buy a refillable drink when we first arrive and get it refilled often. We bring Kindle Fires for the boys to play on during the second half, but they don't get them until after half-time. We buy goodies, like cougar tails, popcorn, etc. to keep them happy. We will buy meals too if the game time is during lunch or dinner.

My boys love to cheer and yell and jump around and sing the fight song. They look forward to the games, and love to go. This week will be a bit colder, so jackets and blankets will probably be needed.

I suggest you buy your tickets from the ticket office and choose seats near the aisle so you don't bother many people with the frequent bathroom breaks boys typically require.