How do you launch Pages / Numbers / Keynote to a blank document automatically?

In Pages and Numbers, go to Settings > General and under "For New Documents:" select "Use template" and select "Blank" then "Choose." I have already created and set blank documents for both Pages and Numbers with my preferred settings, so I have selected those in these screenshots. But you don't need to do that, just select "Blank."

Sorry, I don't use Keynote, but there may be a similar setting there.

Numbers->Settings->"For New Spreadsheets"

Choose which template to use.

It does not open up directly into that template, it still opens with a Finder window where you then click on "New Document". The difference is that "new document" will use the chosen template vs sending you to the template chooser.

I've never quite figured out Numbers when it comes to this. In version 14.5, one of my computers automatically creates a new document when I open Numbers but my other one brings up this Finder window first. I have never figured out why they are different. In 15.1 they both bring up the Finder window.