Welcome back! Your son will love the fiddy, both my boys did, and countless others in the neighborhood
I remember when I taught our first son, just started with throttle and brake, leaving it in 1st gear for a while. When I finally explained the gear shift, that first upshift and the incredible joy and amazement on his face was priceless, and is forever burned into my memories

His first question after that ride was, "how many more (gears) are there?"

2006 CRF250X -JD kit, R can/PMB endcap, CCC mods, 05Rcam, flatland rad guards/skidplate, street legal
2005 CRF50F -stock