Getting rid of one and done would be a front burner issue for me.
Then a total revamp of t he G-League system. Give teams the tools they need to develop younger players. I have no clue how that actually looks though. At least an extra round in the draft. Some sort of roster that is 20-22 players big with 15 on the NBA roster and the rest on your G-League team roster. Give teams a few years of control over young players so there is incentive to develop them. Just copy/steal from hockey and baseball since both have decent minor league systems.
Less French players.
Smaller regular season schedule. Expand the playoffs to offset the lost money from less reg season games. Possibly some expansion of the playin games. I don't know.
Do away with conferences for playoff seeding.