I want to be a professional ethical hacker but I am just a beginner in c+, what should I do?

You should try doing online courses of Ethical Hacking from sites like EdX, CourseEra, etc.

If you want to become a professional ethical hacker, start with initial, learn all the basics of hacking! You can go for CEH (certified ethical hacking) course which is a good course for all the candidates who want to pursue their career in ethical hacking! Good luck!