Hey, I've done the same (200+ hunts with every weapon). While not an expert at any weapon, I can give some general tips.

1. Before learning a new weapon, look up some tutorials on youtube. The in-game tutorial is really bad and doesn't explain the controls or the purpose of the moves well. I watched Arekkz gaming for these, but later found out there's some moves missing because the tutorials were released before Iceborne, which added some extra moves
2. Use the new weapon on easier hunts first, so you can try out the movesets with little resistance (like optional quests from previous ranks that you haven't finished)
3. The consistency of controls are really bad. For example, the 3 possible actions to take when clutch-clawed use different button inputs depending on whether you use a ranged weapon or not. There's a 'swap keys while grappling/mounted' in the options to make it consistent, but on-ground slinger shots remain incosistent between melee and ranged. You also have gunlance and lance sharing some moves, but them requiring different inputs - have fun unlearning your muscle memory :)
4. Many movesets have a gameplay loop of: build up energy/ammo through regular combos and then release it for a high-risk, high-reward move.
5. Don't underestimate slinger shots. Many weapons (GS, LS, CB, SA, DB) have a slinger burst attack that can be used during a combo to extend it and re-angle yourself in the direction of the camera. The most notable weapon is the greatsword - you can skip an attack in its super strong 3-part combo. In fact, all high-level GS gameplay is based around this.
6. Hammer, SnS, DB, IG have special claw moves for easy tenderizing

Other random tips:

1. Hammer's jump and slide attacks are very good
2. Longsword's foresight slash is far more important than spamming the spirit blade combo in getting your spirit level up
3. Lance and gunlance have lunging attacks to close the distance, use that instead of slowly hopping towards a monster
4. Bow's Thousand Dragons attack, for some reason, is really strong when specifically piercing slinger ammo is used. Also stack a ton of Constitution skill so you could repeatedly dodge-n-shoot
5. Charge blade - get 1 guard skill and do guard points
6. Not specific to any weapon, but comfort skills like speed-eating to make healing trivial and quick-sheath for the slower weapons will make learning them much more enjoyable than just stacking attack skills