If you want to know the steps to building your own pc, here you go in 10 easy steps:
1: Check parts
2: Buy parts
3: Wait 3 days for them to arrive/collect them yourself the same day
4: Assemble it
5: Set up bios.
6: Install software
7: Set up Inet
8: Download and install the latest drivers
9: Install x/Have fun
10: Have more fun
Thats my 10-step program so far. (I've build 2 of my own systems, and in the last 3 or so years ~20 PCs for people I know.)
The only issue I ever had was them shipping orders incomplete but that in general just means I cancel that part and pick it up at a local store for a bit higher price (the choice: wait another 3 days, or pay an extra ~€10,-).
My early systems had the issue of having the PSU die on them after about a year, but since I somewhat 'overdo' them it is one of those parts that basicly doesnt age (you may want a heavier CPU 2 years after building a PC, but the PSU is still pretty much as it was 2 years ago).