1) If you're not staying downtown, there are two surface lots at Pearl & Ross downtown. Drive down there, park, and get on the DART from the Pearl Street station. That's the last downtown station on the way to Fair Park, and the ride is less than 10 minutes.
If you're staying downtown, just walk to the nearest DART station.
2) You probably want to be at the Fair not later than 8:30. Get your coupons immediately--the lines start to get long around 8:30. Get your corn dog and wax-paper cup beer.
3) The State Fair has a good website with maps of the Fairgrounds. I just go in for a corn dog and beer before the game--no need to upset the stomach too much before the stress of the game. But if you want to stress your constitution with a deep-fried birria bomb, have at it.
4) Post-game, losers should depart as quickly as possible. Winners own the Midway.
5) I go over to Craft & Growler across Parry Ave. from the Fair (right across from the DART station). They have a great selection of beers, and there are plenty of televisions to watch the other games. It makes good sense to have a couple beers over there while the crowds at the DART station die down.