Every last person here, Male or Female, Young or Old is was a Newbie at some time. So no worries there.
As for the Snap Caps. Frankly I have no idea how long that little green insert is going to last. (Oh ya, that plastic bullet is a snap cap). I bought some and they come 5 to the pack? Different Calibars different amounts? I'm guessing here. There are at least 2 different Mfg that make them and I think one of the packs actually came with replacement inserts. Don't remember how much I paid, but I did buy one pack from Bass Pro Shop and that I seriously doubt was the cheapest price they go for anywhere else.
Well don't sweat hitting the cans frankly I doubt I could hit them myself, Certainly not consistently, Been to long since I shot a weapon and apparently it was a really bad idea to stop. Recycling is a good thing and I have no doubt you will start hitting them more and more as you get used to your new pistol and how it performs. And even if you miss way more than you hit now, It's still got to be a rush when you see that puppy go flying.