I want to be a computer programmer what should i do

Answer 1

It depends on what you mean by "computer programmer".
- If you mean knowing how to manage operating systems it will be C and and specific OS management (Linux, Windows, Mac OS/BSD, ...)
- If you mean Web programmer : it's wide, HTML, CSS, Javascript +/- PHP, SQL, JQuery.
- Web applications : Python, Ruby, C++.
- Android applications : Java, C++.
- iOS applications : Swift
Etc, ... And you certainly can add languages to my differents lines.
It's more about what you want to do than who you want to be.

Answer 2

cant I study all?

Answer 3

You can, it will take time.

Answer 4

You must understand that it is a life or career long process, you will always be learning and improving. As a hobby, start with languages you are interested in. For work start learning those that will help you in your profession, so eventually you'll know them all.