Like said before, don't try to start with the most powerful beasts.
You'll enjoy yourself much much much more if you start with something "familiar" like a WTCC or a Mini Cooper.
Pick one and stick to it on various tracks. You might be also interested in downloading ghost cars for your favourite track on the same car. Thanks to the raceline, you'll see where you have to brake, how strong, when you have to start turning the steering wheel, etc.
(ghost cars downloads are available from ingame, use the time trial mode from main menu)
Don't be too brutal with the controls. Accelerate, turn and brake smoothly, and you should not be surprised by your car.
Also, don't try to go too fast at first. On the contrary, start slowly, become confident, and then speed up the pace a bit, get confident, and speed up the pace again, etc. Until you reach your limit and spin or go off track. Then you can analyse your error by viewing the replay, learn from it and go back in your cockpit for the revenge
The sole truth in all this is : practice.