Start with something simple. If you want to learn to cook you start by learning how to make a hamburger, not Beef Wellington. The first thing you build will probably not turn out too well, but you will learn from your mistakes. The first time you do anything is the hardest, all sorts of unexpected problems come up. It is better not to frustrate yourself unduly by choosing a difficult project with lots of expensive parts for you to possibly ruin.
Craftsmanship is as important or more important than parts quality.
Practice your soldering techniques, make sure all mechanical connections are tight. Lay things out in a neat manner. Route wires carefully. Your work should look neat. Check all components as you put them in.