When adding a user (employee)

When adding a user (employee)

I have a life insurance agency.  I just hired my first agent to work for me.  

In Zoho, if I add him, there are two options for his teir: CEO and Manager.  I added "Agent."  

The question is, if I add him, can he see my Zoho data or is he completely blind to that info as a default?  

The desired result is that he cannot see my data.

Any help is appreciated.