Nice bag!
I love ByAnnie patterns and have made several of her bags. I think the labels for the bags are done well. You can mix up an A or a B, but when the pieces are named for what they are ( i.e., “strap interfacing”), it makes everything perfectly clear. And the labels are logically grouped for each part of the construction. Not simple, but neither are her bags, which is why we love them.
Annie Unrein has several classes on Bluprint, for making several of her bags. Perhaps you would do better to sew along with a step-by-step class until you get used to her pattern style.