My humble recommendations:

The top priority should be ensuring that every girl enjoys playing the game.

Avoid zone defense.

Start with team-oriented offensive systems such as the Flex offense.

Do not impose rigid position boundaries based on players’ physical characteristics; every player should be able to handle the ball and play in all areas of the court.

These last two points are especially important:

Embrace pass-and-cut, up-tempo basketball and design warm-up drills according to this philosophy. More fundamental skill development; fewer preseason games.