I want to be the best F1 driver in IRacing

Hello!

I bought iracing like 2 months ago and with the lack of content from the start, I did not got stuck with the game.

Since then I've been playing Assetto Corsa and Forza horizon but now the time as come and I want to play IRacing again. So what should I do?

What should I start doing? Just drive? What car then? Buy cars? Buy tracks?