I'd tell myself.......
1. If you think one hand gun will cover all your needs, you are kidding yourself.
2. Buy good holsters.
3. Ignore caliber debates between 9mm, 357 Sig, 40 S&W, and 45 acp for defense work. The debates are irrelevant and all 4 work well, so pick what you shoot the best.
4. Don't let popular gun culture tell you that you need to by an AR style rifle if you don't want one.
5. Start reloading early if you can. It'll be worth it.
6. Never confuse the opinions of more knowledgeable shooters with the facts. They are two different things and may or may not be helpful to you.Firearms are personal items and need to suit the shooter.
7. Be careful of internet hype and fanboyism.
8. Folks who tell you there is a proper technique for shooting are probably right, but that doesn't mean their ideas apply to everyone equally. Do what works for you.