Click your avatar to open the user side pane. These settings are site-wide and not specific to a lab. The logout button and lab selector (if you are a member of more than one lab) will live here.
In the side pane you can update your avatar by clicking your icon and selecting a new image.
User Name and Email Notifications
Change your name and email preference, then press save to commit your changes. If you uncheck 'Email comments to me' you will no longer be notified by email when someone Mentions you in a Comment
Your list of labs will be listed at the bottom of the user side pane.
Create new lab
Below your list of labs is the button that allows you to create a new lab.