Hi , I need help with a code,
i need code that will make my player move left and right (horizontal).

If you just need the basic concept then you can use this.

or as this example has that shows how you can set up simple side to side movement. (just leave off the forward/backward part),

Android options are still buggy but it really just comes down to using code "GetButton or GetButtonDown" etc, as there are several ways to call the same function and assign those buttons,

You can find what the defaults are by checking the input settings as directed here,

This document here combined with the above information should then make a bit more sense.
Unity - Manual: Android mobile scripting.

Hope this helps.