You can access account settings via Spaces Dropdown menu on top left, and clicking on your account name.
Under account settings you can change your name, profile picture, email address. You can also change your passwords and see devices where you are actively logged in.
You can click on Leave space button under account settings to leave current Space. This will not delete any data for example tickets and timesheets that were linked to you.
If you are a space owner, you can not leave the space, but you can delete a space instead.