Same here as above with brackets and blocks.
Dug up grass and weeds then put blocks down every 1.5-2ft, then put pressure treated wood in 4 brackets (2 on top, 2 on bottom for each side), this way I have a top rail as well I can drape a tarp over in rain and keep wood dry (outside in yard not under cover), plus it balances and keeps boards straight longer, and I can stack lighter or other wood on top for my firepit and not mix woods.
I've had one for 3 years now with no issues other than 2x4's are starting to turn gray from being in sun and weather 24/7. I also just purchased four more brackets to build another one out of, thanks to hurricane Idalia knocking down 15 of my only yard shade oak trees :evil:.
I'm thinking about buying two more brackets or more and making segregated dividers so I can keep 2-4 different stages of seasoning wood stacked up, or different kinds of wood, instead of just one open 12ft by 5ft space of wood stacked however I can to balance everything out.