Correction on this: when you max your gold bar you get a Bright Engram, which is basically a lootbox for dress-up items. You can get uniquely skinned armour (always at Light level 10, but you can infuse it), vehicles and ships, and cosmetic shaders that change the colour of anything you can equip.
Hints for fast gearing: blues will drop at around your Light level +5, up to a maximum of 260. Legendary Engrams drop purples and can drop at levels above that, and Luminous Engrams (AKA Powerful Gear) can drop exotics but are limited in how many you can get in a week. The best way to gear is to save all reputation tokens and grind blues from Public Events until you're as close to 260 as you can get. Then cash in all your reputation tokens (Devrim in the EDZ, Sloane on Titan, Asher Mir on Io and Failsafe on Nessus) to get up to 265, get your Legendary Engrams decoded at the Tower, and only then open your Luminous Engrams. At each stage make sure you have your highest Light level of gear equipped, even if you don't want to use it - the level of your rewards is determined by the level of gear you have on.
There are also a number of quests you can do to gain high Light exotic weapons. The easiest and most profitable is the quest for the MIDA weapons; it starts in the EDZ and is available once you finish the campaign.
Lastly, there is Xur. He appears in a random location every weekend and sells a random exotic weapon for 29 Legendary Shards and a piece of exotic armour for each class at 23 Shards. Once you're around 270 Light and grinding Heroic Public Events you'll be swimming in Shards and can buy him out every week, saving the off-class pieces for your second and third character.
If you're planning on rolling alts, weapons can be used by any class so stash things you're not using in the Vault for them to pick up. A word of warning, thoug: don't roll two characters of the same class. They'll both get Engrams from weekly rewards, but once you've opened one the Light level of the rewards is capped for all your other characters of the same class. Roll one each of Titan, Warlock and Hunter instead to maximise your returns.