How i do become sucessful in the entertainement industry?

When I ran a post production facility in LA, we would get 10 resumes a week from kids who just
graduated from recording schools applying for jobs as recording engineers...( a $150k a year job)...
At that point in thier carreer they were nowhere near being ready for that job. I would always recommend taking a client services, receptionist or runner job just to get in the door and learn the business. EVERY entertainment environment has its own set of rules and you will need to learn them on the job as they arent taught in schools. Take the internship, or any starting position you can get. Be curious, ask questions. Offer to take on small tasks you feel you can do. Ask if you can stay late and work on the company equipment. Be eager to help and learn. There will come a day when your supervisor asks you to do something on a real job once they see you are capable of it. Many entry level employees I hired are now in top positions because they did that. Good Luck!

What exactly interests you? Your question is very broad. There are lots of different jobs in the field. From technical, business, creative, producing/directing, sales, etc. all of these have their pros and cons and are right for some and wrong for others.
That said, how do you be successful? First off your "success" depends on you. Some want to work in NY or L.A., others just want a fun job that earns enough to have a good life.
I would say is #1 is your work ethic. Do everything whether it's fun or not the best you can do.
Be a team player. Respect those around you and help out if you can. Don't be a 9-5 guy.
Network and always strive to keep a good report with your peers. This is a small world and I can tell you I have met hundreds if not thousands in my work career. 10 years from now when that choice job is up for grabs, a past coworker may work at the place you want in to. What would he/she say about you and what it was to work with you?

Be a person of integrity. Do the right thing especially when no one is looking.

Always challenge yourself. There's always something new to learn. Learn your job well. In broadcast, for the technical side every shop has its own unique systems. Learning the nuances of how things work can make you a clutch person to turn to when thugs go wrong.

I would major in video production and then set time in your school schedule so you can intern or PA on shoots. Reach out to companies in the area and express your interest and willingness to learn. Ask if you can shadow people on shoots and while there have business cards and ask people questions about what they do, how they got into it, why they did it.

Khalah-

This is a great question! First and foremost, it's good that you're interested in diverse areas. It honestly doesn't matter what you major in. At the end of the day, it's all about what relevant work experience you have and who you know. Start networking with professionals and seeking out opportunities. I started as a runner and grabbed people coffee, and that set me up for my next job. Use each job as a stepping stone to where you want to go. Hope this helps!