Why do I need English

I'm learning English and I want to speak it fluently. I want to go to a school of cinema in California next summer, and it's important that I should speak very well.
I also want to meet other people, and I know, that I can help them with Russian.
Russian is my native language, and I've been living in Moscow since my birth. [or: since the day of my birth.]  [1]
I'm have a bachelor's degree in physics, but I don't like that science. Recently I realized that I have always wanted to make films.  It is really in my way. ?? Sorry, I don't understand what that sentence means.
That's why I'm now making my first steps in this field: shooting music videos for my band (I've been playing rock for 5 years) and writing screenplays.

I'm working as a video producer in a small studio in Moscow, and I'm going to earn enough money to study cinematography in USA the next summer.

[1] A birthday is not the very day you were born, but the anniversaries of the day you were born.  Thus, your first "birthday" occurs one year after the day of your birth.  Although many dictionaries state that the word "birthday" can also mean the day you were born, I, personally, have never heard anyone use it that way; and if they do use it that way, it would be extraordinarily rare.]

Good luck to you.  I hope you'll enjoy your visit to The Golden State.