NEWB QUESTIONS FOR USING THE TX16Wx WITH GARAGEBAND. PLEASE HELP ME OUT.

[Knowmadik]

ok, so i just got the TX16Wx to use with garageband 10 on a macbook pro (OS X i think). I've never used a sampler before and am not very tech savvy. Most of my life i was more on the artist end of the booth, not production. but in the past several years have been getting more and more into learning as much as i can about audio production. I'm moderately familiar with garageband overall though.i have pro tools 10, but no midi controller and not the slightest clue as to how to get started using pro tools, like how/where to find digital instruments, or loops, like come with garageband. and i can't find any free info for the stupid NEWB QUESTIONS i have for pro tools either, so any advice there would be a HUGE BONUS to me joining this site and making this post, which I've never done either of before. but heres my MAIN CURRENT situation: I'm currently using wav and/or mp3 files of drum kit sounds, synths, some vocals etc. that i found for free online. like a pack labeled "D-Block Sample Kit" that has a ton of sounds that have been in many songs by artist from the l.o.x., example:the chipmunk voice singing the intro section to styles p's track "i get high" and so on. I'm easily able to import these sounds into the TX16Wx, and then into the musical typing feature for garageband, which is the main reason i wanted to get the TX16Wx. but i also would like to make brand new samples of my own. i have used a site that converts youtube videos to mps files, bring those to i-tunes, and from there into garageband. but i can't import the whole song into the TX, I'm guessing because its too large a file to bring in all at once. but i don't know any method to chop out the sections of a song that i want, and then get them into the TX so i can assign them to keys for musical typing. i know how to chop up sections with garageband, but no way to convert the chopped section into a type of file that i can import to the TX, and then thru the TX back into garageband in musical typing form. lol. complicated and kinda dumb, i know. its embarrassing exposing how novice i am with this by posting on a site like this. but o well. ANY HELP OR ADVICE WOULD BE GREATLY APPRECIATED. once i can start chopping up songs and making unique samples, the doors that i needed to open for me will be wide open. hit me back as soon as possible. thanks in advance.
-Knowmadik