Handgun ownership is (or should be) a mindset as well as a toolset.

Massad Ayoob reading to be prepared for the court fight after the gun fight. Very sensible and easy to read.

Jeff Cooper and other good gun reading.

Be sure and get recognized training. THEN practice a lot.
Practice 100 rounds of .22 for each 10 rounds of anything bigger. This will keep you from developing a flinch or if you begin to flinch, go back to the .22 to reduce it. (I have to do this after 5 rounds of .44Mag)

I was an evening Range Officer at a local indoor range every Thurs for 3 years. (shot about 15,000 rounds of my own during that time)

I saw many, many people start to get pretty good with .22 then as soon as they brought in their 9mm, they couldn't even hit the paper anymore. I don't like 9mm because of the sharp recoil that seems to ruin marksmanship. Folks wouldn't get so bad so quickly with a .45ACP.

Welcome to full citizenship (and the oppressed gun-rights class).