Pretty simple. At the main menu, tab over to Career and choose New Driver. You will be asked to choose a first name, last name, choose some initials and also your nationality/region. Once done, choose Create.
Next will be the Career Path screen. For the sake of the Zero to Hero achievement:
The Zero to Hero achievement in Project CARS 2 worth 279 pointsComplete the Zero to Hero lifetime goal (start in Tier 6 and go on to win a Tier 1 Championship) you should choose one of the Tier 6 options, either Formula Rookie, Kart One, Or Ginetta Juniors Challenge. After choosing a career, you will have to choose a series in that particular career. After picking one, hit Continue. You will next be asked to pick a team to race for. Simply choose one and you will be asked to sign a contract. Hit
to Sign Contract, then Yes to confirm. Boom! Achievement unlocked.