You need to be more strategic in how you manage the two forms of currency that exist in this mode, in both earning and spending them. The team owner role is deeper, and as the owner the "you gotta spend money to make money" mantra definitely holds true for My Team mode.
As per the modes previously covered, the game options will ensure that the AI Drivers are entirely non-competitive, including your AI teammate. The racing driver role will take care of itself. I would recommend you read this page in full first before commencing so you know everything that lies ahead. In addition, I will introduce in more detail the concepts and strategies that you should adopt for that phase and retain through further phases beyond.
The nature of this mode and its achievements mean that there is not a strict flow in the achievement unlocking order - but they can at least be grouped together in phases of your playthrough based on when you can reasonably hope to meet the requirements to unlock them. Otherwise, you can still make consistent and reliable progress towards unlocking the achievements in this mode by implementing some simple strategies that save you from agonising over every management decision that you will face. There can be a lot to think about, but only if you want to. This year, not only are you a driver, but you are also the team owner of a brand new F1 team.
The My Team mode is brand new in F1 2020, and expands the breadth and depth beyond that of the My Career mode in previous iterations of the game.