As the Account Owner you can do and see anything your little heart desires.
To allow or disallow the things that your team members can do or see, there is a Permissions section in Settings, Users and Permissions.
The three most common Permissions scenarios are as follows:
1) You want the user to be able to do and see anything:
Just click on Make as Admin and you're done!
2) You have a buyer's agent and you want them to see only their own data (contacts, properties, closings, etc.)
That's the Default setting. Here is what it looks like:
NOTE: The check boxes - Checking them gives them that ability.
3) You have a buyer's agent and you want them to see only their own data (contacts, properties, closings, etc.) but you also want them to be able to use - but not alter - all the workflows in the system.
Here is what it would look like:
Take a look at this article here for more details on Permissions
This video here also goes over Permissions, as well as how to add a Sub-User!