So Im really interested in composing and creating music, but I can't play any instruments. GarageBand's ease of use and variety of instruments is stunning! Is there a program that gets as close to GarageBand's quality and functions in a similar way? And if it's necessary to note, I want to make music with the same quality and variation as that of Undertale, so I hope i'm asking for something reasonable. Thank you for your time and have a great day!!!!

Realistically, I don't think you'll find anything that is 100% free that does what you want. That being said, I almost always recommend Reaper for any audio work. It's not free, but there is an unhindered demo that technically never expires- it's well worth the cost though. You could use this to edit MIDI and host VST instruments, as well as any other mixing/mastering/editing/etc you might need to do.

I've never tried a VSTi in Reaper that didn't work. ¯\_(?)_/¯ But you're right, there's basically no built in instruments, but there are free ones out there.

Maybe there are better tools for the job, but probably not for the asking price of $0 (initially at least) for a great full-featured DAW. FL is probably a great tool for more of the midi/loops kind of editing, but it's more expensive, especially if you want the full-featured version. As soon as you start looking at much else, price goes way up as far as I've seen.

To be fair, I haven't done much shopping around for DAWs either recently, so if there are reasonably-priced alternatives with a similar feature set, I'm all ears.

heap(er) or free software can sometimes not sound as good.

For VSTs yeah, probably. I don't do much with virtual instruments, but I've gotten a fair bit of use from the free TAL stuff. For learning, that could be a good way to go- costs nothing to play around with it.

Should I not touch music seeing that most of the good stuff costs money

Nah, go for it anyway. Free/cheap stuff is not "bad". I've produced a couple of albums, and a tiny bit of music for games, using mostly free VSTs. Reaper is not an inferior product to other DAWs by any means- it just doesn't have a lot instruments bundled in, and some of the built-in plugins are a bit ugly to looks at (the ui is simple, but the sound is what's important), so you'd have to find plugins to do some specific things, but that's no reason not to dive in.

Another route might be to find any generic MIDI editor, or one of those apps that does guitar tabbing, and use those for composition, then import the MIDI into whatever you're comfortable with for mixing and instrument sounds.

If you truly want to go free and use a modern windows computer, I would suggest using the windows release of LMMS. Its not exactly as nice as using the more standard DAWs out there (ProTools, Cubase, Sonar, Reaper, etc.) but it can do a lot of what you need to do in a DAW to make music. Vestige will allow you to run quite a few VSTis as well, which unless you want to use basically a bunch of synths and oscillators you will want, because most of the stock stuff in LMMS is quite heavily electronic. If you are looking for some basic free VSTs to use, check out Plogue's Sforzando so you can play sfz files. Sonatina Symphonic Orchestra is a good easy way to build orchestral pieces, as well as VSCO2 Community Edition. DSK has a lot of fairly basic VSTs. Musyng Kite is a large library of free (not always great) instruments. Also check out bigcat1969's site for a lot of cool free stuff.

Heh, good thing I found this thread.

First of all:  I use LMMS, a free DAW.

Second of all:  I have more experience with LMMS than anybody else I've ever met.  I have about 11,000 hours.

Third of all:  I am currently working on remixing EVERY SONG in the ENTIRE UNDERTALE SOUNDTRACK.

So, not only can I tell you that LMMS is the best for your purposes, but I can even prove it to you:

(Link to playlist: https://soundcloud.com/douglas-the-awesome/sets/remix-of-the-entire-undertale)

EDIT: I suggest skipping around in that playlist.  Almost all of those songs are completely different genres compared to the others, so if you don't like one, that doesn't mean you won't like the others.