The top level gear has 2 parts, one is dropped on astral runs and the other part must be crafted (with mats you get from astral runs and amalgams you can get from pvp and other activities, or can get them by exchanging at the npc close to the auction house).
To craft: can visit the forge at town, or the Astral Academy (i suggest this one the first time, you may have a quest there that teach you how to craft items). Also can buy "green" hammers there to obtain mats from drops from the astral runs. And can get turn on the daily quests you get each day (complete them to get extra gear boxes).
Astral: open the "group search" function (ctrl + m), go to dungeons and "join" an astral run (you can press "go" but will go only with the people in your party, or alone, and will need to pay for the mercs), and can hire mercs to fill the party, for free.
And you need astral keys to get mats for equipment. You get 14 keys per day, if you run out of keys and still go on astral run you won't get any shining shards, i believe they are called now, but instead you'll get shining stamps or whatever it is that gives you dust if you hammer them.