In order to make a career in acting you should join a theater in high school to develop your skills and to get a exposure so, that you can perform in fronr of large audience. You will also get some experience. 

If you want you can also take a degree in drama program. It is not necessary but i will add value to your career.

Go on auditions build you strong network. so, that you can get your big break.

You can also make your resume and hire a good agent. 

All the Best!!