Visit the Office portal (www.office.com) and click "Sign in"

Once signed in click the "OneDrive" icon

Then navigate to the folder where you want to create the new file and click "New" in the top left, and then choose the type of document

The file will now open in a new tab. Click "Share" in the top right

By default anyone you enter will be able to edit this document. Click the "People you specify can edit" button and you can then choose to untick editing if you want view only access

You can also choose to make it public or public to anyone at your school if you wish