Whether an account was created for you or you have created your own account and a site moderator just approved it, you'll receive a one-time login link by email. Once you are logged in, you should see your email address in the "Account Settings" section. If your email address changes you can make the corresponding edit directly in the CoLab yourself—that is, you do not need to have a new account created for a changed email address.
If this is the first time you're logging in, you will need to set your password to something that you will remember. First enter your preferred password (masked for your protection) in the "Password" field (1). You'll notice that in addition to a password strength indicator (2) the system will also provide tips for generating a stronger, more complex password (3). Confirm your password by re-typing it into the "Confirm password" field (4):