Clicking twice to edit filename - what are the reasons for this pattern?

1. How to edit file name without double clicking?
2. Which steps must be followed to change the name of a folder in Windows Explorer )?

How to edit file name without double clicking?

Enable single click to open (inside any folder click the View tab > Options > Single click to open an item). Double click on the icon or other list categories if you have it set like that, just not the name. Simply press enter if you already have the file selected.

Which steps must be followed to change the name of a folder in Windows Explorer )?

Open File Explorer by going to My Computer, or by pressing Windows Key + E on your keyboard. Find the file you want to rename, select it and select Rename on the ribbon (or press F2 on your keyboard). Type the new name you want the file to have and press Enter.