This is an skill based achievement but can be achieved with a little grind. Everything that happens on a race count towards a rating and all ratings are turned into a final score which represents your skill, consistency and safety so this means that you will need to do clean overtakes and close laps times to improve your rating.
But I recommend trying to get all medals in all tracks to improve your TR(track rating) because not only it is easy but once your TR has reached 99 which is the maximum it can't go down.
And if you're wondering what is the amount of points needed to reach each level here they are:
Bronze:0.001-7.999
Silver:8.000-8.999
Gold:9.000-9.499
Platinum:9.500-9.999
In case you reach certain number and don't receive the appropriate category just keep playing and after some time in the middle of the gameplay they will award you probably because it's necessary that have some experience to receive these titles