I'd suggest reading through the various guides found here, training your pet in the training center, and doing as many battle quests as you can every day. The weapon guide thread in that list usually shows pretty good weapons for that tier, and tier 1 is a quick tier to go through, so don't spend too much on a tier 1 weapon. The only exception to that is a Phoenix Quill, you will use that forever, but it's pretty expensive right away.
If you have any specific questions, don't hesitate to drop in the battle chat thread, most people there will help you with whatever you need :)
Also, the site has its own guides. Here is the newbie guide, and here is the more detailed in-depth guide