event creation restriction
Thanks so much for reaching out and for your interest in our products!
One way that you can achieve the results that you are looking for is to assign a category to each high school. This way, they will only create events associated with a category, which you can then display via a shortcode with Events Calendar PRO.
You can limit admin capabilities to your users with the addition of a third-party plugin, such as Members, so that they can only access the content that you want them to have access to.
I hope this helps to clarify things for you! Please let me know if you have any other questions!