I didn’t know anything about the Blue Snowball, but I googled it and it looks like it’s primarily being marketed as a podcasting mic. I didn’t find any reviews of people using it for music. It’s $63 new on Amazon. I’m not sure how much the other stuff in the Craigslist bundle is worth.
— Begin quote from ____
I have no idea what I need if I don’t buy one with a USB connection
— End quote
If you get a mic without a USB connection, you have to supply power for the mic some other way. Phantom power units start pretty cheap ($30 to $40) and go up, depending on your needs. I have a cheap little phantom power unit with a single XLR connector, but you can use other things. My guitar effects processor has an XLR connector, so I can use it as a preamp, too.