Thanks man. It's too bad you're on PC, we'd be tearing it up on xbox. I'm basically gonna be playing nothing but destiny for the next month or two due to my living situation right now.
Don't get me wrong though, the PC version is fucking slick. The meta is also a little different due to there being no aim assist. Hand Cannons are trash on console, only a few good ones, but apparently they're killing it on PC.
The current meta right now is a good scout rifle (Nameless Midnight is amazing, get three for each of your characters, but a good energy scout rifle is the Mananan SR4, I think it's called. Crispy snipes with explosive rounds on both weapons), a good mid range auto rifle (Uriel's Gift is top tier due to having great stability and High Caliber Rounds. It makes people flinch in PvP, ruining their shots and it majorly flinches enemies in PvE) or a fast time to kill short range weapon (Last Hope is the best sidearm in the game, it just doesn't have great range and apparently sidearms aren't the best on PC, so watch for that and see what you think).
As for power weapons, experiment with what you like, there's no right answer there really. Some tips, however.
Rocket launchers - These are actually your bread and butter for killing bosses and clearing adds in PvE. They can also get you a few good noob tube kills in PvP, so they're a nice all around weapon type.
Notable launchers:
Curtain Call (nice reserve of ammo, 6 shots, and it explodes into a cluster bomb. That's 1 big explosion and then a lot of little explosions. You want rockets that have this perk, it's top tier)
Blue Shift (not the best, but nice, just doesn't do anything in particular)
Sins of the Past (the raid rocket and apparently the best one in the game)
Wardcliff Coil (this is the exotic rocket launcher and mother of God is it good. It fires a massive spread of little rockets that can do a fuck ton of single target damage, if you can hit it with all of the rockets. You have to practice with it though, you will kill yourself with it a lot if you aren't careful. Shooting from the air is good, so jump in the air or get up high and fire down on the enemy. It'll clear adds and make soloing public events the easiest thing in the world. It also auto loads heavy ammo into itself when you have it out and walk over a heavy ammo brick)
Shotguns - Hawthorne's Field Forged Shotgun is the tits. Full auto, crispy, smooth like butter. Get it. I'm sure some others are good too, but Hawthorne is awesome and she made a top tier shotgun. Go her. The Legend of Acrius is both the exotic shotgun and the raid shotgun. You have to do a quest to earn this weapon. The quest has a lot of pieces. It includes beating the raid and doing a specific nightfall strike, the Arms Dealer. It's annoying, but basically you earn the quest from killing Cabal, it goes into your power weapon inventory, you complete the various parts of the quest, eventually unlocking the shotgun itself. Then you have to go do things to upgrade the shotgun and make it better.
Snipers - Eh... These are so situational and you have to get heavy to make them work. I really wouldn't recommend them for PvP at all and for PvE, you can just have a good rocket instead. Ones to look out for though are any that have explosive payload, outlaw, or elemental explosion. A Single Clap is a good one, I hear. D.A.R.C.I. is the exotic sniper and it's also just alright.
Grenade Launchers - Trash. Play of the Game can be earned from Shaxx, heard that ones alright, but GLs just need work to be viable. The Prospector is the exotic GL and it's a monster for PvE and Public Events, so eh, it's not all bad.
Fusion Rifles - Main Ingredient. You can get it from doing normal strikes and turning tokens into Zavala. It's good, you'll like it. The Merciless is the exotic fusion rifle. It is the tits, it will shred bosses. You want this exotic.
Swords - Holy shit are these great fun. You use swords to clear adds in PvE content, but they also one shot people in PvP. Swords to look out for are ones that give you heavy ammo back after doing a thing, like getting three kills rapidly.
Notable swords: Each of the classes get their own unique sword from Cayde after beating the campaign. You can't use the sword of another class, unfortunately. Titans get Crownsplitter, a heavy type that swings slow, but does massive damage if it connects. Not recommended for PvP at all, but great for PvE. Warlocks get Eternity's Edge, just a fantastic all around weapon with a unique look. It's not too different from other swords anyone can get though which is a shame. Hunters get by far, the best sword. It's the only light type sword in the game. You run faster with it out, you don't even need ammo in it for that to work. You run like a little weeb ninja with it and while its range isn't the best, it attacks extremely fast. Great for PvP, especially on a stealth nightstalker, and decent in PvE.
Remember! When using a sword, you don't have to use the main fire button. I don't know what the controls are on PC, but on console, swords have two attacks. One that uses 3 rounds of heavy ammo, one that uses 1 round. If you've got that figured out, make sure you only use the 1 round attack in PvP. That'll still get you a one shot kill without burning through all of your heavy. Careful though, once you run out, that's it. The weapon can still swing, but it's slow and doesn't do any damage really. That's useful in PvE for swords that get ammo back, but not for PvP.
And from there, notable weapons in general:
MIDA - You get this from completing the world quest of the EDZ and doing tasks for Banshee. Don't do it until after about 270 power, maybe 280. The longer you hold off on it, the stronger your MIDA will be when it drops which means its easier to get to higher power, so keep that in mind.
Nameless Midnight, Mananan SR4, for reasons mentioned
Better Devils, Old Fashioned, decent hand cannons. The Better Devils has explosive payload, like the Nameless and Mananan. It's a great weapon all around. Old Fashioned is just nice and simple, what it says on the tin.
Origin Story, Scathelocke, Uriel's great auto rifles. Origin and scathelocke font have HCR, but they're kinetic and they're wonderful. Origin has rampage which gives you more damage per kill up to three kills. Great for PvE, good for PvP. Scathelocke has a 600 rounds per minute stat. It's a great weapon, but gets beaten out by other autos at 450 RPM. Just depends on preference. Uriel's, as I mentioned, has HCR and is slick. Good stuff.
Last Hope is the only sidearm you really need, but experiment, you never know what might be good for you.
Pulse rifles don't really have a strong place in the meta. That said, Nightshade is a good one and you can get it from Zavala after doing his strike quest once opening up the tower. You can choose between origin story, Nameless, or the nightshade. Any of these are good, but I suggest origin or Nameless. Two great pulse rifles though are the Vigilance Wing exotic and the Time Worn Spire you can earn when the iron banner comes around. Vigilance is great in PvP, it has a five round burst. It eats ammo like crazy, so not recommended for PvE. Time Worn Spire is great in PvP as well with a fast time to kill. Also okay in PvE, but there are much better kinetics for PvE.
And that's it. I can't really think of any other weapons for you to worry about.
If you have any questions about exotics or want tips for a specific class, let me know. I have one of each and they're all close to being max power. I know the different armor pieces pretty well and the class specific exotic armor gear as well.
Any question at all, I can probably answer in depth. Just let me know.
And just to say it, Scout rifles are basically the meta right now. They kill well and from far away. Get to love them, but don't be afraid to experiment as well, PC is a different beast from console due to the lack of aim assist. The meta there is shifting in different, fun ways, like the hand cannon thing I mentioned earlier.