To find your profile and update it, click on your name (shown here as Test test) which will show on the far right hand side of the menu:

You will then see the following drop down menu:

Click on Profile'  You will then see all of your profile details as below:

As you can see, within your profile, you have the options to update your personal details such as your name and contact details by using the pencil icon.

Admin users can also edit billing information from this screen using the Add new card dialogue.