what to do with my credits?

I just started playing and I leveled up. I got a wheel spin that gave me 30k credit. I’m still on the story part where you get the three races at the very beginning. My question is, if I spend the 30k on a new car, will that mess up my story mode? Or if I upgrade my car a bunch, will it mess it up? Thanks.

As you progress each new event will be in a new or different championship class. It’s best to save your credits until the next event and then buy a car for that championship. Often the upgrades are more expensive than the cars. But if you like to play everything you do pretty much pays off in credits and they can accumulate pretty fast but while you are still in the beginning it might be best to horde them a little until you have a stockpile.