Picked up the young adventurer books thinking that they had simpler kid rules, but I guess they have no rules (you’re supposed to just be motivated to buy a starter set or something). So I played with my niece (8) and nephew (5) without any rules and they LOVED it. Right after our first short adventure they wanted to play again.
I basically just made them roll for anything they wanted to do in combat and took turns as usual. Let them roll to respond to any attack back at them. No HP, just descriptions of injuries.
They loved upgrading their swords into go-go-gadget everything weapons with buttons to shoot spikes, or light on fire - so I let them. Even the boat they needed had to become a sword upgrade magic inflatable raft haha.
Anyway, highly recommend for young players.
Check out DND adventures club.