For inside the stand I use a couple coats of primer, then a few coats of white latex exterior. I also seal the bottom several inches with flexseal.
For the outside of the stand it depends on your plan. Primer and exterior latex if you decide on paint. I prefer the look of wood, however, so I use stain and then several layers of General Finishes exterior polyurethane. It's water based, so almost no smell as it cures. I used it on a neighbors Green Egg cart about 10 years ago. It's held up remarkably well, although he does cover it between uses.