I've been trying to do the same only to find the whole thing frustrating af. My goal right now is to A) draw wireframes of websites, B) workflows (similar to wireframes with added arrows), and C) an image of Calvin of C&H fame.
I've used Procreate, Excalidraw, OneNote, Notability, etc.
<rant> All of the tutorials are like "Here is where you can select a canvas. Here is where you can select brushes. Let's choose this brush..." (Why?) "Then change the setting to this..." (again, why?). I'm beginning to hate videos in my search results.
If I want to actually accomplish one of these drawings, I pick up a pad of paper and pencil and I'm done in 60 seconds for wireframes, five minutes for Calvin. I have yet to be able to do it after hours on my iPad. </rant>