I need to mention VSCode since nobody has mentioned it yet. Awesome lightweight text editor, lots of extensions to download.
EDIT: Here's a 20 minute talk on why VSCode is a great text editor :) https://youtu.be/anvYeA1pWlk
I use Notepad++. It is pretty simple to use (not a vast learning curve). It's a popular and good text editor that new coders use alot.
I have also used:
* WordPad (which is ok for getting ideas down for smaller programs)
* regular NotePad (not recommended, unless you can't use anything else)