You generally should not have to access Turnitin directly, and instead you should be enabling Turnitin when creating a Brightspace Assignment if you want to use Turnitin (see instructions here).
However, if you need to submit a paper to Turnitin outside of Brightspace, you can log into Turnitin directly with your CCC email.
Go to: https://www.turnitin.com/login_page.asp?lang=en_us
Click “Forgot your password” and put in your CCC email address and last name. You will receive an email with the next steps.
Once you are logged in, you can then upload a document for similarity checking.