Your account page is on Office.com. Just sign in, click the arrow next to your name, and then click My Account.
What’s on my account page?
If you have an Office 365 Home Premium subscription, on your account page, you can see a list of everyone you’re sharing with and the computers where Office is installed. You can also install Office, manage all installs, invite people to share your subscription, view your billing history, edit your payment methods, and access services like Skype that are included with your subscription.
If you’re sharing someone’s subscription, you’ll get your own account page where you can install Office, see the list of your own computers where Office is installed, manage your installs, and access your SkyDrive account.