The more complete your profile is, the easier it would be for people of similar interests and values to find and contact you.
Just click a green edit icon next to the info you want to change or upload on your profile page
If you want to stop using your account completely, you need first to deactivate it. Choose "deactivated" (text-link leads to the respective page) in the Account Status menu in the general settings page. Deactivated account won’t be seen or found by other users, but can be restored within 1 month. If not restored, it can be deleted after 1 month.