Like many here, I would say start with a 22lR and then move on to a 9mm. It's cheaper ammo and both guns will do what you want. The 45acp is a great gun but for a novice, you will a want a full size heavier gun to feel comfortable and then it will be too big to carry. A good mid size 9mm like a Glock19 or if you want to go more high end, look at a Sig Sauer P229 in 9mm.
"I'm a good guy with a gun" What do I care if I give up some freedom or rights?....The Goverment will take care of me. This kind of thinking is now in the majority and it should concern you.
"Ask not what you can do for your country, but what free entitlements you can bleed from your country"