1. Head over to https://myaccount.google.com/security  


2. Scroll down to the "How you sign in to Google" section and find "2-Step Verification"


3. Add 2/4 of the available options by clicking one and following the steps until two have green ticks


4. Finally click the blue button "Turn on 2-Step Verification" to enable this fully.


Note - Any problems, submit a ticket and a technician will be able to help