Accomplish the indicated achievement to get the corresponding number of Gamerscore points:

Welcome (5 points): Finish a race.
Anticlockwise (20 points): Win at Adria, Kyalami and Imola in the same Single Player Championship.
Wooden Medal (15 points): Arrive 4th with less than 1 second from 3rd in a Single Player race.
Not a Rookie Anymore (15 points): Complete a Single Player championship.
Bad Settings, Good Driver (15 points): Win a race on Monza setting your wings at maximum inclination.
Bad Conditions (15 points): Win a race with a completely destroyed car.
Hard Victory (15 points): Win a 1 lap race using hard tires at hard difficulty level.
I did it for race 2 (10 points): Arrive 8th in race 1.
The Real Thing (10 points): Win a Single Player race on Legend Difficulty with all aids turned off.
We Care a Lot (9 points): Watch all the credits.
King for a Day (15 points): Gain 43 points in a single Championship weekend.
A Step Forward (10 points): Win a Single Player race on Medium Difficulty.
Album of the Year (15 points): Unlock all the pictures in the pit.
Angel Dust (10 points): Win a race using Andrea Chiesa.
Clockwise (20 points): Win at Portimão, Vallelunga, Mugello, Monza and Magione in the same Single Player championship.
Direct confrontation (15 points): Win an Online Quick Race.
Enduring confrontation (15 points): Win an Online Championship.
Delayed confrontation (15 points): Win an Online Time Attack race.
Moonwalking (30 points): Win a race crossing the line in Reverse.
Star 69 (30 points): Win a Single Player Championship with Kristian Ghedina on Legend Difficulty.
Back to School (15 points): Complete Driving School.
School's Out for Summer (20 points): Complete Driving Academy.
When I Kissed the Teacher (15 points): Complete Racing School.
Graduation Day (20 points): Complete Racing Academy.
We Don't Need No Education (30 points): Complete all Licences with an 'S' evaluation.
Always in front (15 points): Achieve a Pole Position in every race of a championship.
On the top (20 points): Win a Single Player Race at Legend Difficulty.
First Lesson (5 points): Play your first Licences exam.
Four Circles (5 points): Win a race with the Audi RS4.
New Winner (10 points): Win your first race.
New Champion (30 points): Win your first Single Player Championship.
Hard Level Champion (40 points): Win a Single Player Championship at Hard Difficulty.
Legendary Champion (60 points): Win a Single Player Championship at Legend Difficulty.
The Strongest Rookie Ever (10 points): Win a wet race at Imola with Martini.
Roaring victory (5 points): Win a race with the Jaguar.
International Driver (30 points): Win at Portimão and Kyalami in the same Single Player Championship
Silver Arrow (5 points): Win a race with the Mercedes C63 AMG.
Cup Collection (20 points): Win a race in every circuit.
Bonus Point (15 points): Achieve the fastest lap in a Single Player Championship race.
I Like 360 (36 points): Score exactly 360 points in a Championship.
New Furniture (10 points): Unlock a prize in the Pit.
Algarve Aquapark (15 points): Win a Single Player wet race at Portimão at least Hard Difficulty.
Team's Mascot (30 points): Unlock the dinosaur puppet in the Pit.
Mind the Gap (30 points): Win a Single Player race with at least a 10" gap from 2nd place.
Almost There (15 points): Win a Single Player race at Hard Difficulty.
Been There, Done That... (15 points): Complete a race on every track of the game.
Introduce Yourself (10 points): Win the first race in a Single Player Championship.

Additionally, there are three secret achievements:

Secret achievement (80 points): Unknown.
Secret achievement (15 points): Unknown.
Secret achievement (70 points): Unknown.