Simply follow these steps to locate your Account Details:
1) Click the user icon on the top right-hand side of the navigation bar.
2) Choose the first option from the dropdown menu, which is named 'Account Details' (indicated by the red box below).
Under the first tab 'My Account' you'll find the option to update your email and name.
The next tab is 'My Company Details' and this is where you can update any part of your company information such as address or phone number.
The 'Change Password' tab allows you to choose a new password (not any other user on the account).
Finally, under the 'Users' tab, you can invite / add new users. There is no limit on how many users you can have, and there are no financial implications for adding additional users.
To find out more about users, read this useful FAQ.