So... what should I try first? Lots of things to choose from, it's kind of overwhelming. Any substrate or species suggestions? I was thinking of starting with either oyster, enokie, or shiitake but it would be nice to try something new out i suppose.

How big is that PC? If you can fit a filter patch bag filled with sawdust substrate shitakes are an option. First thing is to prepare some agar & get whatever cultures you want to work with started. Next is preparing jars of grain for spawn, that's probably where you'll be using the PC the most. Depending on your choice, you may or may not need to streilize your substrate, straw & compost subs just need pasteurization. Hope you have good results whatever you decide to do. I have to start my grain today for portabellos & either oyster or shitake.
Nothing beats fresh homegrown food, enjoy.
C1

Cultured, I think it is 6 quarts, I'm not sure though I'll have to check the box. It was pretty cheap, I got a good deal.. I pretty much figured that I wouldnt be able to really do anything big with it, but I just wanted something that could at least sterilize agar or a smaller amount of spawn. This way if I come across a species that I want to culture, I have something to sterilize with and I can preserve my findings. When I get into doing larger grows I will look into something bigger. For now the goal is just to be able to create cultures. I could even use a small amount of sterile spawn, get it colonized, pasturize (with peroxide or something) some larger substrate and grow that way.
I really appreciate all of the cultivation advice and help that you have given me, I owe you.. If you ever need anything or I find something interesting while hunting, I'll send you some cultures.

Just glad to help. Your thanks & me knowing I've helped someone out is cool enough. Good luck with your grows.
C1