This article explains how to change your Facebook privacy settings to make your posts, friends list, profile information, and albums private. Instructions are specific to Facebook on desktop.
How to Make Your Facebook Account Completely Private
A quick way to block everything you post in the future is to set your default sharing option to Friends, not Public. When you make this change, only your friends will see your posts.
To access the Facebook privacy settings and tools screen:
Select the arrow in the top right corner of any Facebook screen.