Do yourselves a favour and savour the career. Don't just blitz through it. as fast as you can to get some meaningless digital achievement or trophy. Set the AI to challenge you - you shouldn't be even placing in the top three in every race, let alone winning them. Run full practice and qualifying sessions, and full-length races. Run full damage. Full damage. Never quit or restart, even if you jump the start and get an immediate drive-through penalty or if your car is wrecked at turn one, or if you blow your engine two laps from home. Dust yourself down, learn from it and pledge to do better next time. Don't sweat finishing last, but take great pride in finishing better than your last race. Be proud the first time you finish in the points. Enjoy the thrill of fighting in a pack for nothing but pride. Race clean. Respect your opponents. Enjoy watching the leaderboard evolve through the season and take note of the drivers above you.
It's incredibly rewarding.
And if you really want the most from it and your schedule allows, do practice, qualifying and racing as a real-time race weekend, on the actual days of the week that they happen in-game, and feel real tension and anticipation build throughout your week as track day approaches. It's amazing.