Quote (Decadence @ 8 May 2016 00:04)
Ok. Just beat act 5. Does this have the normal nightmare and hell levels like D2? After beating the final guy(forgot his name) it just has me exit to main menu and I just clicked continue and it started from act 1 again.
After you beat the campaign you can start doing Adventure Mode, which is a somewhat free-roam type of mode. There are difficulties, but they are sort of an overarching difficulty. Like if you've played other games and you can freely change your difficulty throughout the playthrough; it's exactly like that, except there are quite a few: Normal, Hard, Expert, Master, Torment 1 - 10.
In Adventure Mode you can do Nephalem Rifts or you can do Bounties. Open up the waypoint map in Aventure Mode to see the available bounties, they'll have a " ! " over the waypoint if a bounty is active. Completing all 5 in a specific act rewards a "cache", which has various blacksmith plans and cache-specific loot.
As for doing Rifts, you open up a rift by going to the pillar next to Orek. Think it's called a Nephalem Obelisk or something to that effect. Basically rifts have you go through maps, kill mobs, and eventually kill a Rift Guardian which will drop blood shards and various loot.
TL;DR: Play Adventure Mode, do some rifts and bounties. Grind for loot!