Answer 1

Computer experience? If you posted this on a computer, then surely you have! Unless you're talking about programming.

You can start somewhere. If you're interested in web development, then you can start off with the front-end. HTML5 course, moving to CSS afterwards and then, JavaScript. From there, you probably have understood quite a bit about programming. Then you can go into PHP and SQL, which are for back-end. You store data, such as usernames, passwords etc by using PHP to transfer them to a database, which is what SQL is for, if I'm not mistaken.
There are also other languages than the above. Such as Ruby and Python.

If you're interested in mobile development, then you can look into Swift(For iOS) or Java(For Android).

Answer 2

Just start a course

Answer 3

start coding and have passion in it