Welcome to the sport! This is a great activity for the family!!
Almost any of the staging areas at the popular riding spots have flat areas where the kids can ride around and get lots of experience. In the high desert off the I-15, Wild Wash Rd., Hodge Rd., Stoddard Wells Rd., Dale Evans, etc. As for places closer to home, I'm not familiar with what is down in Orange or western Riverside Counties (probably not much I'm afraid), but out this way there is an area behind Cal. State San Bernardino and one in Cajon Pass. Pinnacles, behind Lake Arrowhead or Cactus Flats are nice if you are willing to do a drive into the mountains. There is supposed to be a new SVRA (state vehicular recreation area) opening in Riverside Co. some time in the future, but nobody is absolutely sure just where.
Camping out is a great way to learn too! When my kids were beginners, I would take them to Ocotillo Wells, and I would sit in camp and keep an eye on them while they rode all day around camp.
Feel free to ask us about any particular spot you have in mind, and we can rate it for you. And, those displacement limits for the safety course are ridiculous!! All they are doing is keeping a lot of kids out of the course! To SMALL a bike is just as dangerous as to big a bike. See my post http://forums.atvconnection.com/mess...did/365655.cfm