You don't have to be a computer wizard to run an emulator
Okay, if you're a newbie to this, I'd advise you to go for the VICE emulator. Along with CCS64, it's the most popular one, but it's more user friendly. It uses a simple GUI (graphic user interface) the likes of many Windows-based proggies, so you'll get used to it pretty fast.
To run any C64 game you've downloaded from the Net, you just need to launch it from VICE. To do so, use the "File" menu at the top left corner of VICE's screen, and select "Autostart disk/tape image". Then, use the pop-up window to browse your harddrive and select the C64 file you want to run. Double click on it and off you go!
Of course, there's much more to it than this brief walkthrough might suggest: cartridge and raw tape dumps, multi-disk games, sound and video options, etc. But I think that, for a start, you only need to know what I've told you. You'll be able to learn more and more tricks over time.
Oh, and welcome!
Galileo Fígaro... Magnífico!