It can feel a bit aimless at times but the most important thing IMO is to start using your hands. Get your hands on some cheap scrap tubes and learn to file and miter them. Buy some cheap lugs and learn to work with them. Find a way to hold onto them and file and shape them. Miter the tubes and set them in those cheap lugs and braze them. After brazing cut the joint in half and see how well you did in getting it full and absent of voids.

My point is that nothing will substitute for experience and time at the bench. You will, just like everyone else, make lots of mistakes and that is the point really. You will learn from them what works and what doesn't.

The schools out there can give you a good basic intro to how stuff works and shorten the process a good bit and may be worth it to you (based on your time and money available) but even after school is over you will be alone at the bench figuring stuff out on your own and learning to solve those problems is key.

Dive in and make some stuff. It will be frustrating and fun.

Dave