Solved

Bit confused

Hi Sonny, welcome to the game. There are a number of guides which you will find useful...
As a new player this is probably the most useful: 2022 - iGP Manager complete guide
This will also help you as you become more familiar with the game: The Mechanics of Chassis Development

IMHO the most important thing is to find a good league where experienced managers will assist you. At the moment there's a bit of an issue with lack of activity in the Rookie tier but if you stick it out you will enjoy the game and the community.

Depending on your preferred time to race there are two leagues which I can recommend, both are well established and there is associated Discord server where you can ask questions and get advice from experienced managers. The great news for you is that both of these leagues have a new season beginning today.

Velocity Racing League

Velocity Racing League 2 - SUSPENDED

Note: I edited the post, I realised after originally posting that Velocity 3 does not have a Rookie Tier.

All three Velocity leagues alternate each season between refuelling and no refuelling so you get the best of both worlds. Additionally, Velocity 3 (which is offline) also alternates between 50%, 75% & 100% race distance so it's six seasons (18 weeks) before you race the same format as before. This stops people copy/pasting the winning strategy from the season before.

Welcome Sonny to V1.