Tips on Purchasing Lower Bowl Tickets?

Hi everyone! I've decided to be at the NRG stadium for some games since I currently live in Houston. However, I couldn't figure out what's the best way to buy tickets. I want to be on one of the games against Bills, Lions and Ravens on lower bowl but I don't know if I should buy the tickets on general sale or just wait on the game day to try my luck on resale.

Thanks! 🙂