Of course, you don't have to go to college, but going to college is a shortcut for you to become an actor. Many stars in China were born in regular classes.
If you take the exam, of course, it is mainly about talent and acting.
You can't register as an actor, but you can register as a university major, such as acting, broadcasting and hosting.
When an actor doesn't specify when to debut, it depends on your ability and whether anyone appreciates you. There was a little hero Lin Hao in Wenchuan earthquake, who became famous after Wenchuan earthquake and acted in many TV dramas.
I think it still depends on your family's interpersonal relationship and economic strength. If you rely on yourself, it will take a long time, or you have outstanding talent.
If you don't go to college and sing well, you can make yourself famous; If you are very talented, you can go to the director; If you can write a script, you can also find someone to invest in you. In short, you have to let everyone or the director know that you are a plastic talent.
PS: Good luck!