One track in Guernsey runs birthday parties events. The single thing that decides whether this works is age and height, and it catches people out constantly.
Always check both. The gap between a 1.20m and a 1.40m minimum is the difference between an eight-year-old driving and watching.
Purpose-built junior karts fit smaller drivers properly. Some tracks also fit remote speed limiters so staff can build a nervous child up gradually.
Children mixed in with adults have a worse time. Ask whether junior sessions run separately.
Food, a private room, a podium and a trophy make it a party. Without them it is a driving session with cake in the car.