Have been to a few races at Talladega, not Texas, but in general yes a good idea to plan to arrive early.
What I was a bit surprised by, the first time I went (2008), was the area outside the track that is sot of like a "Midway" area at a fair. I knew it existed.... but had not considered how much time I might want to spend there. Vendors selling souvenirs and such, food, and LOTS of sponsors with interesting displays. And "schwag", lots of freebies given away by some of the sponsors. Have to be a bit careful not to grab a bunch of stuff that you end up carrying the rest of the day, including not getting stepped on at your seat (not much point in getting a freebie rolled up poster if it gets stepped on). You can check out and do a lot of stuff for free (I never bought anything).
Read the track rules about what you can and can NOT bring in. No ice chests, nothing big. But the ones I went to, I could bring a "6 pack" sized flexible insulated bag, that I put water and cokes inside of, plus a frozen gel-pack. The cost of a bottle of water, or soft drink, or other beverages are crazy-expensive at the track, so take as much as you may need, up to how much you can fit things. Also IIRC, any bags had to be clear, so security could see more easily what people were bringing in. Sort of like the limits getting into an NFL game or other big sporting events.
One of my favorite sponsor display freebies, fans could get inside of a car (special built for display, with a drivers door that opened), and have their photo taken by the sponsor's camera system. Filled out a short form that included info for e-mail address, got home and there was a link in my e-mail for the photo that had been taken.