Need UX/UI design feedback from experts

I am the PM for a startup called Wildkard - we are building a platform for youth athletes, and their coaches / parents. The big idea is we get everyone from the team in one place to chat about games, practices, online training, pro sports, etc... Admin features get users in the door and then community keeps them engaged.

If you have any time for UX/UI feedback I'd be much obliged. Screen images are below and this is our website: https://wildkard.io/ and you can find us on the AppStore or on Play.

Thank you so much!
Sam