Under my account I remember I could edit my profile under "settings". But now I don't find the feature there. Has it been moved somewhere? Thanks.
Your Meta profile has a settings page but it does not allow you to edit your profile (about me etc.), because it's automatically synchronized from the main site. As @n8te says, use the main site for this, e.g. by going to https://unix.stackexchange.com/users/edit/current.
That's the main site; the 'Edit profile' link is missing on meta: