I haven’t been there since before Covid, but I went there numerous times in the 2010s. Always bought a GA ticket for INDYCAR and IMSA. There’s a big mound/hill at the end of the keyhole straight that gives you a good view of the cars coming and going. Nice place to sit too, just bring a blanket. Gets crowded though so get a spot early.
You can also stand all along the back straight, up to the carousel. Sight lines actually aren’t bad standing along the fence.
I don’t remember which, but during some feeder series you actually had access to the grandstands along the back straight. Don’t know if that still applies ever.
And as with racing circuits like this, you can bring your own food, drinks, beer, etc. It’s a nice track, good memories there.