Learning generally boils down to "Repetition or the avoidance of pain", some people learn by doing, some by watching and some just have to pee on the electric fence.
Whether you think that you can, or that you can't, you are usually right. Henry Ford
Sounds like it will be a great build. The square firebox is a good choice and will save you headaches along the way. Do your homework before you start and you will have an easier build. As for making it draft correctly check the calculator on this forum. You can also get plans for your build for a small fee if you prefer someone else works out the details
I'll definitely be asking some questions...right now I'm just trying to soak up as much information as I can. I've been running numbers on the calculators like crazy lately and even dusting off some of the drafting skills(from highschool...so not great lol) drawing some scale prints.