Can you bring your own water bottle in? Blanket(s) for the lawn area? I read that chairs need to be lower profile below 9" in height. Any insights appreciated!

I don't know about the water bottle but you can bring your own blanket

Unopened bottles. Blankets, yup. And they have rental chairs too.

When the venue was still Starplex, a few months ago, I was told that it changes from show to show; that it depends on the artist playing, and what their preferences were for people bringing items like blankets. I'm not sure if that's changed now that it's Dos Equis. To be safe, I typically just rent a chair through the Live Nation app a few weeks before the concert. I've tried to call the box office but, 100% of the time, nobody had answered. 🤷🏼‍♀️

You can bring a water bottle too. When we went, they said no outside food or drinks (unless it was a water bottle with water).