I need to get the Dirtbikes out in 2023- opinions on mentoring a kid who doesn't get the opportunity to ride

I just got an 85 ytm 225 3 wheeler and started teaching my 12 year old step son how to ride.
I still have a 2000 xr 100 that was my kids before , as well as a 2010 Polaris 90 quad , a 92 lt250 Suzuki quad racer, a 2008 drz400 Suzuki and 2 83 ytm 200 3 wheelers one is a runner the other is complete but a bit crusty and unknown.
I have not been riding in the dirt for many years but now with a youngster with desire to ride I'm going for it.
Just like cars it can build a life long hobby and commaradary.
Definitely the 125 would be a good starter bike.