You need to think about something: Would you like to train a PF/C duo or a SF/PF duo?
This is because SFs and Centers are hard to train together. It would be much easier to either try to make them both bigs or forwards. I personally would make them both forwards. As for training I would rotate between OD and ID and then work in passing until your 20 year old gets up to mediocre passing.
Murray/Harris/MPJ/Grant/Jokic - 2020 NBA Champs