I plugged in my zoom g2, and the sound was horrendeus
I plugged it in via adapter to my mic-slot.

I'm completely new to home recording, so do i need a separate soundcard for my pc? Is there some setting in zoom g2 that needs to be turned on when recording via pc? I have basic gaming pc, and basic speakers, i know speakers contribute to the matter as well.
Favorite and a really cheap option that I love is Pod Farm,
Can grab a Line 6 UX1 for around $100 or so that comes with the software...works by itself as an external soundcard, so lag is virtually non existent.
You just need to learn how to use the tools you have.. Learn how to send a compatible signal to your DAW, learn how to set unity gain, learn how to use adapter cords and interface. Read the sticky or go to tweak heads and get up to speed.