Go to https://www.cambridgeone.org , click on 'Get started', choose 'Learner' and 'Next'. You will be asked about your age and the country where you live. (We need this to make sure we comply with your country's privacy laws.)
If you are old enough to create an account, you can choose to sign up with your Facebook or Google account, or with your email address, so we can send you a verification email as part of the setup process.
If you are too young to create an account, you'll need to ask your parent to do it for you.