In order to set your page so only user's you allow can see it, you will need to:
1. Select the option to SHARE.
2. You will see a box that says "Who Can See This Page". Select the group you want to view the page.
3. If you want to share with a certain person outside of a group - such as a friend, another student, or teacher - right below it there is a section called "Search For People in bulb". Type the username of that person.
4. Or you can create a private link to share with individuals or non-bulb users. When sharing a private link only those with the link will be able to view your page.
5. Hit APPLY SHARE SETTINGS