If your sig is up to date, you wont be able to find much at your level I dont think. When you get to level 12 you can quest in the barrens, there are a lot of humanoids there drop linen (especially kolkars) and at around 18 I think they will start to drop wool. Once you are in the barrens killing humanoids you will have no trouble leveling your first aid.
Aside from the barrens just look for any humanoids, all drop cloth I think. It would help to be sure of your level, and know where abouts you are questing at the moment, assuming this hasn't already helped you enough.