I am a new user and am learning Scrivener. I notice that my page text (Courier New 14) displayed at 100% appears smaller than I expected. Visually, it looks more like 10pt or 11pt font size. Is the font size unit metric default set for pixels, points, or something else? Is the unit metric changeable, for instance from pixels to points? If so, how?
The fonts are set in points. You may need to adjust the zoom setting. It sounds like you’ve located it, in the lower left corner of the editor screen, a little box with a % and up/down arrows. I found Scrivener’s default setting too small for my eyes, and increased it to 130%. You can click on the % box and choose a setting for the current project. You can change the default (for new projects) by going to Tools > Options (or press F12), and then the Editor tab. That’s also where you can change the default font and paragraph settings for new documents. Existing documents can be changed to whatever defaults you set here by Documents > Convert > Formatting to Default Text Style.
As DavidR says, you may want to play with the zoom a bit. Some programs like Microsoft Word do some internal zooming, which Scrivener does not, so 100% zoom in Word is about equivalent to 135% editor zoom in Scrivener; at 100% zoom in Scrivener, you’ll find the 12pt text looks smaller than the same font at 12pt in Word at 100%. That said, remember you can also completely override the formatting during compile, so in the editor you could work in a different font size (and different font entirely) from what you want to use in your finished manuscript.
Interesting, MM, I didn’t realize that about Word’s internal zooming (which sounds like a case of over-caffeination, actually).
There’s a fancy word for it, but it’s the end of a long weekend and my brain shut off a while ago. 
It’s about compensating for resolution and big techie stuff like that…