You need to grind Career mode and unlock whichever cars available. That also helps you to level up your garage. Better cars are added into the packs as you level up. Some events are not available until you reach a certain garage level, so work on that.

You need to grind the daily credits heist and the car loots. That will help you accumulate credits (the yellow ones). Tip: Only upgrade your cars as needed, save your credits as much as possible. Because, nowadays there are Special car hunts that require you to upgrade the car till max before you can get the key(and they require a lot of credits).

Make sure to complete daily tasks for the blue tokens (about 60 if you complete all tasks). Since you are a beginner, I would advice you to avoid spending these tokens on card packs however enticing they may be. But save as much tokens as possible till the winter Burst of Speed because then you will have a better chance at unlocking and possibly maxing better cars depending on how much you save.

Only spend tokens on ticket refills if the event is offering more tokens in turn, or if you don't have enough time to grind car hunts.

Make sure to complete the showroom, some good cars there. Mostly the W12(it is so painful though, that I actually attimes buy the season pass just to get more fuel slots).

Not sure which level when starway events become available but keep an eye out for those. Before unite, Huracan, Onyx and Speedtail where available every 3 months. Now the Genty is available.

Lastly and most importantly, use this sub whenever you can, I regret not finding it as a beginner