Archive your active projects to free up more space, you can then manage your archived projects, delete or restore them in the future.
Click on project settings in the home menu and then click on archive to archive the project you're currently working on.
Archive projects so you can start new ones if you don't have a pro account. (there is a project limit on the other account types)
Keep your projects safe and make sure you don't delete them or overwrite them.
Go to open projects and then use the filter in the search bar to find all of your archived projects.