are people so totally dense that they can't even figure out that you start doing the first things you can do and it'll take you to a few skill level points? i mean WoW even highlights the recipes you can make based on the ingredients you have in your inventory, you just have to look at your crafting menu before posting a question.
come on, you can't be hand-fed through your whole life. i might understand if you asked about skill level 100, or 254...but 15???
turn raw scraps of leather into light leather, or make light leather armor kits to add to all the armor pieces you and your friends find throughout your adventures. that alone will take you to at least 40 skill. it might go higher but for sure you can hit this level.
never mind, i re-read your post and realized you are asking basic questions for things you haven't even tried yet. i bet you didn't even read the other posts about how to start up leatherworking, you just needed your own thread for your own responses.