This is the third and final season. You have to complete the Junior WRC season first and then the WRC 2 season. After WRC 2 season make sure you pick a contract with a WRC team. Not another WRC 2 team. Or you will have to play another WRC 2 season.
The most important tip for the WRC season: pay attention to this ingame accomplishment for the Legend achievement: Complete 14 objectives within the same season
The reason: the WRC season only has 14 stages. Each stage has 1 objective. If you fail 1 objective you have to start a new WRC season. Some objectives rely on a single track. If you don't pay attention and miss the objective there is no way to undo it. Only to start a new WRC season.
When you quit a race or dashboard and close the game you will automatically get a 1 min (iirc) penalty and move to the next race. So avoid doing that. You can restart a race at the result screen with X.
As far as I can tell the targets are somewhat randomized and not always the same.