On School Loop Standard 2, you can add Hidden Folders from the Add New button in Site Center. Then, just move anything you need hidden into your hidden folder. You can have as many as you need. To move an object, just click on it once and then the Move button is at the top.
Here's a screenshot of adding a new hidden folder:
Q: Can I hide a page without creating a folder?
A: Yes. Learn how to hide a page.