Any tips?

Hi, I bought a used copy of gt7 and I’d like to get started. I played a lot of gt sport with friends and when the server closed (I’ll never forgive you Polyphony), I decided that one day I’d join gt7, and now I’m in. Can you share your tips, suggestions and ways to make this experience more enjoyable? I’d mainly play online with friends and others, so everything related to how to get credits, choosing cars, customising them ecc… Thanks for the help!