Dividing screen in csharp

I’ve been trying to achieve the desired result for hours now with no luck.
I’m new to programing, tried watching/reading tutorials, but couldn’t find what I need.

I’m working on a simple game. I want the player to move left when I touch the left side of the screen, and move right when the right side is touched.

How could I divide the screen into left and right area in csharp?

Thank you!

screen.width/2 anything less than screen.width/2 = left side anything greater = right side

and its the same for unity script or c#