Follow the steps below to remove yourself from a social group:
On the mobile app, navigate to the Friends tab
At the top of the Friends screen tap on the drop-down menu under Feed
Tap the drop-down menu and select Groups
Under Your Groups, tap to select the group you would like to remove
Tap on the 3 dots in the top right corner of the screen, then tap Leave Group
Follow the steps below to make your profile private:
On the mobile app, go to Profile > Settings > Privacy and toggle Incognito to ON