You can change your profile's content by simply clicking on 'more', next to your profile picture, on the left-hand side of the screen » 'Edit profile' » select the section you'd like to edit » make your changes.
Note: on smaller screens, the 'more' option is in the bottom-right corner.
You can manage your profile content while in the App by tapping the sidebar menu icon ☰ » tap your profile picture » tap the blue pen of the section you'd like to edit » make your changes » tap again the blue pen to save your changes.
You can manage your content while in the App by tapping the gear-wheel icon » next to your profile picture, tap 'View profile' » tap on the edit icon (the pen, top-right) » select the section you'd like to edit. All your changes are saved automatically.