N4S,
http://coloradojuniorkartingclub.com/
Contact this series. They have an excellent program for growing younger racers, are very self contained. Seems they are growing many of Colorado’s future racers and are more than help full and welcoming to new racers.
There is a schedule on their website, go check out a race and I think you will get all your questions answered. The dads and grandpas are very eager to help.
Welcome to a great sport to share with your grandchildren.
Rick