Step 1: Recomended (strongly!)
Your kid should be pedaling and braking well,
They should wear a helmet
they need to be under voice control (stop when you say "stop")
they need a flag on thier bike also, as they only come up to the top of the hood on most cars while riding
putting a bell or horn on the handle bars gives them (and you) a quick way to give turning directions as at this age," right "and "left" may not make imediate sense. "toward the horn side" or away from the horn" will make much more sense
they need to wear sneakers or sandals that firmly strap on, flip flops come off easily and let toes get nailed by stuff on the ground. barefoot allows toes and even the foot to get crunched or cut easily.