I finished my first season ,22 races so I'll tell you what and how , but im from Poland , use translator , lets go
Collect money because you spend the money you earn on a new driver , after contracting a new driver the season is coming to an end , only then do you get money from sponsors etc ,
you choose a new supplier of engine, painting, etc. as far as I remember, the price of the engines is 4 million and more.
Most important: In the first season you have to collect cash and spend only if you are going to buy a specific driver, when you have a notification about an expiring contract with your driver, check who needs what , this is just an example, eg leclerc wants a second aero level , so upgrade it to second tier , leave the rest and collect cash , when you collect money for charles, upgrade your center as you like , I hope I helped at least a little
One more thing: at the end of the season, the news will come that changes to the aero and the body are being prepared for the next season, you will have to correct the installed modifications for half the price of resources.