F1 2021

As the achievement mentions, you can do this in any career mode you like.

I obtained this in Two Player as i just wanted it done, and TP is something i'm not focusing on outside of achievements - also you need to already complete a season in Two Player, so it was just quicker to continue for this achievement.

Two Player can be boosted with a second console and account (like a friend or roommate) and a second copy of the game if you didnt buy it digitally (if you have it digitally, use your home console for the other account).

Home Menu -> Solo -> Two Player Career.

You can set the season for 10 races, set your weekend (qualifying format), assists, and AI. I think the shortest race laps you can do is 5.

You can skip practices and go straight to qualifying or even the race. This mode is exactly like online, in the fact if paused, the AI still drives.

You need to go to the first practice of the first season, but once out on track, you can and Retire. Once back at the workstation, you can go straight to the race.

You need to drive and complete at least 1 race, and then you can retire the rest of the 9 (if doing 10 races). For the second season, you can retire from all 10.

If you dont have access to do it this way, i'm sure many people on this site would be willing to help out, and you can even create an LFG (Looking for Group) post on the actual xbox, only needing 1 person for this achievement, i've seen a few on there already. If all else fails, shoot me a message on xbox (obviously same as my handle here) and i can help you out, although i dont have a mic as of right now.

This achievement will unlock after you advance from the race stats screen after the podium celebration from your last race in your second season.

For the first season, i raced all races, but had a Mechanical DNF, but the first season achievement still unlocked. Someone asked if you could retire from races and have it still count, so starting from my second season:

I skipped straight to the race on both accounts, paused before lights out, and retired (on both accounts) when that become an option just after lights out, and after the podium, race stats, and advancing, the achievement popped up. So, it seems, you are able to retire yourself from each race without needing to rely on mechanical failure and have this still count. That should make things even quicker, especially in a 10 season race.

You can also put this towards some other achievements such as:
"Perfect Record"
"World Champion"
"Constructors Champion"
"Tracked Addiction"
"1 Lap is all i Need"
"Qualifying Master"

as well as complete 50 hours track time.

(i'm sorry i don't know how to include achievement links on mobile xD)