CC Handbook is worth reading. Tactical training is irreplaceable.
The Weaver Stance is great, two hands are great, hearing protection is great, however a BG is not going to wait until you get into your preferred stance until he tries to cap you or your partner - and God forbid if there is more than one BG. When split seconds count you do what you can. Attending a series of LFI classes with Ayoob would be a good start if you can afford it. I am sure others are similar, just depends on your proximity to where the classes are and what you want to accomplish.
Your brain is your first asset for awareness and assessment, cover is second asset, ability to adapt third, hitting the BG next. Practice, practice, practice... drawing from you actual carry rigs, strong side, weak side, primary gun, backup gun, all possible positions, one hand, two hand. Also, if you travel in packs, like my wife and I, or my sons and I, practice coordination between the two (or more) of you. That is one reason this family has standardized our carry weaponry. Standard weapons, standard mags, standard speedloaders and knowing how the other person is going to act. A gunfight is not a scripted exercise. If you have ever been fired upon or even held on, you can relate, let alone ever having to fire back. Kind of like, "hold on a second bro while I rack my slide...." Ain't gonna happen. Cocked and locked or a DA wheelgun.
Lastly, never go anywhere with a gun that you would not go without one. That tidbit of info is priceless and lifesaving. If you wouldn't walk into the hood without your shiny new Sig, don't do it at midnight. Also, remember the majority, 70 to 80%, of encounters occur at less than seven yards and basically the same percentage occur in subdued lighting. Target practice at 50 yards at noon is not quite relevant. If someone is firing at me at 50 yards I am running and looking for cover, not returning fire.
Respectfully and my two cents.