.22 LR Goodness
My first gun was a Ruger 10/22.
For several months it was all I had.
I bought it so I could learn to shoot, learn gun handling, and have some fun.
I also realized that, although not ideal to the purpose, it would certainly serve for HD if it came to that. I didn't persuade myself that people would be intimidated looking at a rifle more than a pistol, and I didn't kid myself that it would be easy to handle a carbine in a house.
It was what I had.
After I learned to shoot and after I had some experience with gun handling, I got an M1 Carbine and a Marlin Camp 9 on the same day. The "manual of arms" for those two rifles is essentially the same as for the Ruger 10/22, and they deliver substantially more punch.
Since then, I've gained some proficiency with pistols and added another couple of rifles -- where "couple" is a .223, a .30-30, a .357 carbine, another 9mm carbine (CX4), and another pair of .22s -- well, okay, another trio of .22s.
I believe I could defend my home with anything in my gun cabinet. The small calibre stuff I shoot accurately even when firing rapidly. The bigger stuff I shoot "acceptably" (meaning I may not hit a two-inch circle, but Mr. BG is gonna hurt nonetheless). And the rifles (mostly carbines, actually) are easy and natural for me.
I'm not nearly as worried about the ability of a .22 LR rifle to ruin a bad guy's day as I am about my ability to stand my ground and do what must be done under stress.
I certainly wouldn't want to go up against a Sicilian when death is on the line.
If you're starting with a 10/22, then use it to become proficient.
When finances permit, maybe think about a 9mm carbine (Hi-Point makes a cheap but good shooter) or (for a bit more cash) a .357 carbine like the Marlin 1894. It shoots .38 special, too, so practice ammo won't break you.
Take your time. Go handle various rifles. As you get better with the .22 rifle, your grasp of what works for you will improve. You may learn that you love pump actions and hate lever guns. It has to work in your hands, so advice will only get you so far.
You know, there are other High Road members in Massachusetts. You could spend some time with one of them and answer a whole bunch of practical questions.
Just a thought.