The Witch Queen is here in Destiny 2, and a whole lot of story stuff has happened. You should absolutely try the Legendary story campaign if you haven't. It might be pretty difficult, but luckily, Xur is here with a fresh batch of Exotic weapons to give you a leg up. Here's where you can find him and what he's selling.
Head to the EDZ's Winding Cove area to find Xur this week. For his weapon, Xur is offering the Sunshot hand cannon. Hunters can pick up the Lucky Pants leg armor; for Titans, there's the Doomfang Pauldron gauntlets; and for Warlocks, Xur has the Skull of Dire Ahamkara helmet.
This isn't a great week for Xur, though--You'll find that all three peices of Xur's Exotic armor are relatively low-stat, falling in the 48-50 range instead of the usual 58-66 range. That may well be to avoid giving any players an extra advantage in the race to complete The Witch Queen's new raid and become World's First. This week, you're only going to want to pick up one of his Exotic armors if you need it for your collection.
Xur also now offers Hawkmoon and Dead Man's Tale random rolls, since the activities that give those Exotics as rewards have been removed from the game with the release of The Witch Queen. Xur's DMT carries Vorpal Weapon, which is one of the better perks to get on the gun for PvP activities, along with Steady Rounds, while Hawkmoon includes Eye of the Storm and Alloy Magazine. Those rolls are expensive though, requiring an Exotic Cipher, a huge amount of Glimmer, and an Ascendant Shard.
For Legendary weapons, Xur has a few items that might make decent additions to your arsenal. His Gnawing Hunger auto rifle carries Auto-Loading Holster and Multikill Clip with a Handling Masterwork, a fun roll for PvE; the same is true of his Dire Promise with its Auto-Loading Holster, Swashbuckler and Stability Masterwork roll. For PvP, Sojourner's Tale is a decent get with Auto-Loading Holster, Opening Shot, and a Range Masterwork, while Xur's Frozen Orbit might have some useful versatility in both kinds of activities thanks to its Snapshot Sights, Clown Cartridge, and Handling Masterwork. None of these are god rolls, but you might have fun with them.