Yes, you can! Adding a new client using the same email you use for your coach account 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.

You can assign yourself Actions to remind yourself to do certain things related to client onboard, or Metrics that gauge certain practice-related tasks for yourself.

 Also, since the freebie client is an actual client, you can log in as that client, and see things from the client side.