Have you checked the articles listed in the left-hand column of the home page of this website? Lots of ideas on gear selection and packs there. These articles will steer you away from getting stuff that is so heavy that you'll very soon want to replace it!

It's generally advised to wait to get your pack after you get the rest of your gear. You should match the pack size to the volume and weight of your gear, rather than vice versa. In the meantime, rent or borrow or find a used cheap pack.