XsymbolicangelX

I have installed the blender software, and i have decided not to spend money on avistar and have a 3d female model close to sl uploaded on blender. I'm very eager to learn and i know how to use templates and textures on gimp etc... But what is causing me all of the confusion is how do i even begin to know how to create clothes by itself, like actually the object of pants or a shirt, how do i actually make that? Or is there a place where i can download pre-made clothing to upload to blender? Thank you so much for any of the help i can receive it is greatly appreciated.