This article will give you all the tools you need to successfully set up your Profile and start using all the awesome features it has.
When you've signed up for Plus, you can claim you very own subdomain (which will be called a Profile or Plus Profile from now on). To do this, please make sure to log in, and you to go your Plus Panel by clicking the 'Got Plus?' button in the top right-hand corner of the screen. Check out this GIF for the steps to follow:
Once you're logged in, go to 'Profile' and you can adjust all details concerning your account and Profile.
After filling out your Profile name, make sure to save your changes. This will instantly activate your Plus Profile. If you like, you can also set your wallpapers while you're fiddling about in that section. For some additional info on the size and format of wallpapers, check out this article.