Your first mistake was buying something from one of the big computer "manufacturers". They just assemble cheap parts and double the price.
Your second mistake was wanting to ask them about audio. That's like asking the cashier at McDonalds what color the cow was that your burger came from.
How long have you had the computer? If it's only been a few days, try to return it. There are guys on this forum that can build you a system that will be faster and more stable for less money.
Any soundcard that comes with a mass produced computer is going to be garbage. My friend bought a Gateway a few years ago and had them set up the whole system for audio. What a joke. Came with NO audio apps, cheap motherboard, and a cheapo soundcard.
I also recommend the Delta 44 for your situation.
And you will need a mixer, that's what we mean by preamps. A mixer is a bunch of preamps. Since you'll only be recording a few tracks at a time, I suggest Studiomaster, Allen & Heath, or an old Soundcraft, depending on your budget and how many channels you need.
You'll probably also need a mic or 2. The Shure SM 57 is the world standard. It works great for most standard instruments (guitar, drums, bass....) at a decent price (about $80).
Good luck, and please take the advice from the people on this forum. You've come to the right place.