Whats with "mining"? How does that work?

Don't do it the costs outweigh the rewards unless you have cheap electricity (which still you need good hardware) and/or you are able to put a big investment down for a mining farm, doing so knowing the currency can crash. Some people mine at a loss even because they speculate the currency is going up.

Using your own PC is a bad idea, it will fry your GPU, it's a heavy load.