I am coaching 12 and 13 year old girls but first most of them this is their first time playing. I cannot figure out how to teach them to box out no matter how hard I try. They don't seem to be able to find their girl, turn to box her out, track the ball, and grab the ball and hold onto it all at once. It may be because of their lack of experience in just playing but I'm not sure how to help them. Any advice would be appreciated. Thanks

Maybe you've done this, but grab your assistant and show the girls what it means to box out. Explain why it's important. Give them a good example, so it's clear in their minds. Should only be about 3-4 key points. Touch opponent, turn around quickly, arms out and wide, and using butt to push the opponent back. Honestly, the biggest deterrent sometimes is players not wanting to make contact. You need to get them used to that.

Break down the drills in a progression. The drill below has a close-out step, but ignore that at first. Start with the girls already making contact. The defense is already turned around in the blocking out position with their hands out, and butts low. On your whistle, they try for 3 seconds to keep their opponent from getting the ball. You can do this drill without the circle and use five separate balls in a horizontal line spread out a bit, so players aren't crashing into each other. Add in the close-out step.

https://www.breakthroughbasketball.com/drills/closeoutbox.html

Emphasize this during the games. Have a parent or sibling of a player keep track of block outs during a game. Give the kids updates during timeouts and half-time. Don't worry too much about grabbing the rebounds at first. That will come as you keep practicing.

Hopefully, this helps some.