Assuming that you're a level 3 Artisan at present, find the Wholesaler Society in your home village and join it. Then do some harvesting in Forest Ruins or similar area, take the stuff to the crafting tables and see what you can make.
You buy the fuel and recipe books from the merchant in the Society.
Once you reach level 9, go to QH and visit Alfred Ironforge on the docks to choose your subclass. If you still want to be a Jeweller by then, choose Scholar.
Word of Advice - up to level 9, have a play on all the crafting tables to see which one you enjoy the most