If your goal is to learn how rendering works, then building your engine will be a great journey.
Think about it:
- your first window
- your first triangle/poly
- rendering an object
- making a camera
- your own shaders
And so on.
You could get a book as a starting point, for example dx 11 book from frank d luna (assuming you "know" and can code in c++)
Hehe, thanks, i already read (most of) Frank's book, that's where i started.
I already made all those things you mentioned, and that's how i came to this odd conclusion :-)