Backyard firepit safety - what am I missing?

Just built a firepit ring with my 6 and 9 year old using some pavers and landscape fabric underneath. We're planning to do s'mores this weekend but I'm paranoid about safety. Have a small sandbox about 8 feet away, no overhanging branches directly above. Is there anything else I should be thinking about before we light it up? First time doing this with the kids.