devtrackers.gg
Not a server full of the best duelists in the game. A level 13 will have 0 understanding of what is even happening. He probably doesn't even know how to riposte yet. He should learn the basics first. It's like fighting in MMA as a newbie against people like Khabib or Mc Gregor going all in while you can barely throw a punch, good luck learning anything.
IMO depends on whether or not the person you're dueling is okay with training you - if they're going 100% effort against you, you're probably not going to learn. But fighting a better player who just uses ripostes or some basic attacks and still kills you (going easy on you) will teach you a lot better than some guy who has no idea what he's doing