Yes, you can! 

If you haven't yet set up a Freebie, adding a new Client, prompts the system to ask you if you want to turn that client into a freebie client. 

This client does not count towards your subscription plan (it's free) and is useful for experimentation and self-coaching purposes.  Also, since the freebie client is an actual client, you can log in as that client, and see things from the client side. 

After you've created your Freebie client, you can click your name at the top right and go to 'Switch Accounts...' to select 'My Freebie Client account'

The first time you switch after setting up your Freebie client, you'll be asked to create a Username and Password (not one you need to remember). This allows you to see things from a Client's point of view when they register their accounts with you! 

Once set up, you can easily switch between your Coach and Freebie client accounts, test things out as a client, assign things to yourself, such as Actions to get things done, a Metric to track a personal/business goal for yourself, and perhaps even keep a Journal.