There are items you can get from mob drops and fishing (and the AH) that when lined up a certain way in your inventory and clicked on produce a summon scroll. When you use this scroll you automatically get a quest, and and after you defeat the summons the black spirit rewards you. Everyone in your party also gets a loot drop from the mob. The reward/loot consist of hunter seals which can be turned in for weapon/armor blackstones (the item used to + your gear) and memory fragments (which restore item durability). So, what you do is, get a group together where everyone has a bunch of these scrolls, and spam them. Each summons only took like a minute or two when I was duoing them, so a full group should down them super fast.
You can then either use the items on your gear, or sell them on the AH for tons of silver. This and grinding mobs is your pve, pretty much.
I've been playing in KR for the past 5 weeks, and IMO the game has a lot of interesting systems on the surface, and great graphics/animations and combat, but there's not really much depth. The fact that the economy is so limited and controlled really lessens the sandbox aspect. Overall, the game is just one long grind for currency to throw into the rng machine. I've learned enough about the game to know I won't be playing NA, but I'm sure people will get some enjoyment out of it before the shiny wear off.