Having your own “cTrader ID” is absolutely Free.
To create one, please go to “Sign in” and click on “Signup” at the bottom of below screen(on cTrader trading platform).
Then, you can register by setting up as below.
You can also create a cTrader ID by just logging into your Facebook or Google account. In this case, the email address you use for the services will be registered to cTrader automatically.