Because I just made this post on another forum and realized it might be useful here, have a copy/pastage:
IMO for beginners to learn the game and not lose terribly 100% of the time:
Good: Katanas (dual-wield or +shield, stay away from two-handing it), Poles, Claymore.
-Poles and Claymore especially are very simple to use and teach the fundamentals well. You can just use one attack all day and work on learning how to time and space it. Katana + shield does a good job of showing you how sword'n'board works without being as complex a weapon to use as Knight Sword/BBS. Dual katanas are a lot like poles and claymore, but a bit tougher to use IMO. Also nice for beginners in that if you can go for a pushlock, it's almost always the best thing to use, so you don't fall into this trap of using the thing that seems really good, but actually isn't. Also for the record two-handed katana is pretty good, but also the most technically difficult moveset to use in the game IMO, except maybe spears. And mages if we're counting that as a moveset.
Meh: Northern Regalia, Great Axe.
-Northern Regalia is a not-as-easy version of Claymore that's arguably stronger. Not really a bad beginner weapon, outclassed by Claymore for accessibility. Great Axe is pretty easy to use and teaches basics. But it has a very focused playstyle, and new players and easily come to over-rely on the rolling attack.
Bad: DBS, Estoc, Spear
-DBS, Estoc, and Spears are all weapons that have dumb easy things you can abuse (two-handed running attack, shieldpoking, and more shieldpoking respectively) that can kind of trap players into this "I want to use this all day" mindset. All these weapons are difficult to use outside of their one easy tool, requiring really smart and precise play.
ABORT ABORT ABORT: Claws, Daggers, Kilij, Spiked Shield, Bow, Mages.
-Claws and Daggers are basically "Stunlock: The Weapon." Extremely gimmicky weapons that will turn new players to ashes and probably never scratch a half-decent player. They will not teach you anything of how to play the game. Also they suck, literally the worst weapons in the game. Kilij is an extremely easy weapon to use that doesn't really make use of the games' fundamentals to do well. Across all levels of play its strategy is the same: run at people and mash R1. So it will teach you how to do that, but not much else. Spiked Shields and bows are sort of situationally good things that you don't want to use as your main weapon. Mages are a long tutorial on how to abuse animation glitches and do mix-ups. Very fun to play as. Not good beginner material unless you have no interest in ever playing a melee build.
The Special Case: Straight Swords are kind of complex weapons. You need to know when to use 1H and when to 2H, and its attacks all have nuanced uses. The stunlock is sort of a new-player trap because it seems really powerful but isn't. You can fall into a bad habit of always trying to land it when you shouldn't, like some other things I mentioned on this list. That being said, if you can avoid that trap, and don't mind having a little trouble at the start, Knight Sword is IMO the BEST weapon for a new player to start with. Very flexible weapon, teaches good shield use, how to identify which tool is right for the job, positioning, roll punishing, pressuring, defense, etc. It's not a weapon that has any easy answers to anything, but if you get good with a Knight Sword you'll probably be able to pick up any other weapon in the game and use it well. I started with Knight Sword and do not regret it.
But yeah if you want a weapon that is easy to use and teaches basic stuff, Claymore or Pole are probably your best bets. They are basically a test of how good you are at pressing R1. Also if you don't care about what your learning curve looks like, just use whatever you want. I've been trying to get into Street Fighter for years and kept getting bored every time because people told me to play Ryu and I didn't like him. Now I'm playing some character who is horrible for beginners and having a blast. I wouldn't want to wish my Ryu experience upon you, so if you're having fun with DBS, stick to it.