Watch an episode of Sesame Street then look at YouTube for videos on herding cats to get in the right frame of mind
Expect it to be fairly chaotic, but the parents will wrangle their own kids. If one of them does a runner, the appropriate parent will go fetch them back.
Don't expect that the kids will actually make any serious attempt to follow your instructions.
Get them in a circle to start. Introduce yourself.
Go around the circle with the parents getting their kids to wave and say "Hi Sari!" So at least the parents might remember your name.
Get them to practice some shapes "rocket shape" "star shape" don't expect much.
Jumping on the spot. Sitting in tuck shape.
Have an obstacle course circuit thing set up before hand. Get assistant coach to demonstrate the circuit. You can talk her through each bit.
Things like walking along a floor beam (parents will help their kids), rolling down a wedge sideways, jumping between a few hoops on the floor, jump off a block on a mini tramp to a crash mat etc.
Get them to start wherever on the circuit. Help where appropriate. Keep an eye out for parents with more than one kid. They'll need an extra hand.
Let them go around this for a while.
Round them up onto the floor in a circle again. Get them to do some really simple stretches, like pike on the floor, touching knees then toes. Then sit in straddle. That's about it.
Some kind of coordination thing, like everyone holds a bean bag and they balance it on the back of a hand outstretched, balance it on a knee (trying to stand on one leg, note that they won't be able to do this, but the parents may try) balance beanbag on their head, turn on the spot with it on their head.
Avoid balls unless you want to spend all the time with the kids chasing them across the floor...
Find out if they give out stamps on the hand, or stickers at the end of class. The kids will get very upset if they're used to getting these and they're not on offer
Ask the assistant coach what comes next, they'll help.
Good luck.
