My personal approach (learned from posts in this forum):
Activate the Note Composer core plugin, and configure it like this:
I created a template named note_composer in the folder that is configured for templates (in the core Templates plugin), which looks like this:

In the source, I select the text that will be placed in the new file. I press command-p to open the command palette and type “note composer” to select “Note Composer: Extract current selection”. I’m prompted for the destination, and enter the name of the new file and then press enter to create it.
No doubt there are seven other ways to do this, but this is the one that I like.