To do any editing, be in the multiplayer menu. You must complete the introductory session. After that, you will have access. Make sure you have pressed to access the Data Hub. Navigating the menu is not as easy as it once was, and is almost confusing. Go to Templar Profile and Edit Templar Profile. Go to Edit Title and to Progression. Now you will be able to select The Recruit and gain the achievement.
You can do this at any point and will have many more options later on. The description is for anyone wanting to get it done right away.