There are many steps to ensuring the privacy settings on Facebook are offering as much protection as possible. This includes the settings related to who can see your profile, who can see your posts, photos of you that others might post and tag you in, who can view older posts and what advertisers can access.
You will need to go into ‘settings’ from the menu bar in the top right corner and choose then click on ‘privacy’ on the left-hand side. You will need to spend a little time going through each of the options. Ideally, nothing should be set to ‘public’.