Wrightyson Hicks will probably be good for your son as you can really blast round at speed and practise his berm and jumping skills, do a few laps easily enough
OP, plenty of natural stuff local that means I haven’t touched Cannock or Pines for ages, don’t see the point in driving to either with all the good stuff around Belper, Ambergate, Matlock area. It’s not all strictly legal though so not going to post up any routes here, but look at Strava for an idea of where to go, then there is also the Peak of course
If your further south then there is some good riding to be had in north Leicestershire, or round the Ticknall area south of Derby