Please sign in on the top right of the website. By clicking your user name, you can choose "My Account": 

The following information will appear:

We have included your information regarding your username and e-mail address. Also, you can edit your profile if you like. 

You can find your subscribed FleetMon plan (Starter, Professional, Business, or Enterprise) on the right side. Here you can manage your subscription by clicking the button. You will be forwarded to the subscriptions section.

An overview of your available credit points is on the right side of this page. For purchasing credit points, please click the button "Purchase credits".