Emmab, when I mentioned the CO2 thingie I included that it's a BICYCLE accessory. You'll want to check out either MEC, who I know carries them, or one of the better bike stores in the area.
Now that you've got the rifle and revolver and have gotten to shoot the rifle and will soon be revolver savvy you'll want to join us at Chilliwack for our monthly black powder shoot. It's a nice trail walk along the base of the hill that serves as the range's big backstop. But pack portable as there's not really anywhere to set things down. So you want a shoulder bag or a vest with lots of pockets.
I'm coming to the realization that the patch and how tight it makes the ball fit is every bit as important as how much powder I use. And the best accuracy I've gotten was with a moderately tight patch which I was able to ram home with only a couple of grabs and which didn't try to peel skin off my hand or break my wooden ramrod. I had to use some .495 size balls recently because of running out of my preferred .490's. I used a thinner patch to compensate but it isn't the right one to get an accurate load. Something is missing or not right for this combo.
I've since gotten a .490 mold and if the balls from this mold work with my old patch material again then I'll likely not bother fussing with the .495's. Instead I'll just melt them down and turn them into a few more .490's.
I mention all this so you can see that the patch and ball have to complement each other. It's not just about the right powder charge. Although the patch is shed within inches of leaving the muzzle it still serves a very important function while in the bore of getting the ball spinning. So we can't just sluff it off.