Hi, I'm pretty much new and I believe I've asked something like this already before but whatever.

I just would like to know how to just improve my guitar sounds. Right now I'm using the low-quality ones on GarageBand.

Some people I think mentioned this
like, amp simulators and cab sims (which I don't understand anything about) and I don't know how to start using whatever they are.

I just want for example, like a Foo Fighters - Walk (or any of that album's songs) guitar sound OR just a better sound! Like rock but better quality (yea I know, I can't get studio quality with GB or whatever ok). Idk, the tones on GB are pretty bad and have background noise or something, maybe i have to play around with them more but yea..

Thanks in advance, I'd like to just know what to do

Last edited by bradrox14 at Jul 4, 2013,
First, and most important: give us some recordings! We need to know what your tone sounds like now. Upload them to a place like DropBox or SoundCloud; or you can use the MP3s section on your UG profile: http://my.ultimate-guitar.com/main.php?mode=mp3

Amp and cab sims are software effects (programs that modify sound, instead of creating it) that simulate the effects of real amps and speaker cabinets. You need one of each; everything after that is a bunch of tweaking knobs and seeing how it sounds. For example, I use Poulin Le456 for an amp sim, and an impulse from the God's Cab kit for a cab sim, and adjust the settings until it sounds good.
You might also need to add an EQ on the end to filter out the mud and fizz. I recommend starting with Poulin LeCab 1.0 as the cab sim; it's easy to make that sound good out of the box without too much EQing.
The most important part, though, is hardware. You'll need an interface. Look at the thread about interfaces to see why, and get an idea of what some of them are like. And keep in mind: you get what you pay for.
I've heard a lot of people swear by Native Instruments' Guitar Rig, but I personally could never get a good tone out of it. I use Line 6's Pod Farm, it's a nice simulator and easy to use. Really though, as is said, is hardware. Get a nice audio interface and then start to think about amp sims etc. If you already have an interface, then it's a case of trying different amp sims, and learning how to effectively EQ your guitar tracks