It seems you have a lack of confidence, and that is understandable.
I think the best method is t...just start. I call over-research,
Paralysis by Analysis
A way to do that perhaps, is to start small. Think of it like a writer who has writer's block! It really is not a lack of ideas, it is that they FEEL their writings are not good
enough, so they do nothing. It can be the same way with building, so I suggest combating that like a writer handles writer's block. They just write without concern about if it is good or bad. With a building a great way to do this, is build a shed....
A shed is useful, a person can store tools and stuff in it while they are starting their main home. If you screw up on some details...who cares...it is a shed. See what I mean. A confidence builder. As you learn, you will see what works and does not.
I have lived what I said. I started with a 2 car garage when I was 18, and it was horrible. The main building was okay, but the cabinets...oh my. But over the years I kept building, got better tools, and now carpentry is something I like.
As for confidence...you can do it, a home has so much redundant strength it is crazy, it will not collapse. And by the way, I have cut my own timber frame beams for my own home by hand, and it went faster, and better than I thought. You will be fine.