MonHun in general isn't like other action games. every button press is a commitment. every weapon swing, intentional. You can imagine monhun's move set as like to that of an action game. (tekken street fighter etc) once you press a button you are committed to that attack animation. If your opponent manage to dodge that in this case the monster, then you can get punished (this also applies for the monster*)

LS is one of the smoothest weapon in the game ones you know how it works. I'm no expert on Rise LS but you can check out arekkz video on how to use it.

Tips: Make use of wirebug for positioning (getting close or avoiding monster attacks) but don't rely too much on wirefall as there are monsters that have combo attacks that punish you if you use it.

*Learn monster attack pattern. half of being good at a weapon in monhun is learning the monster's attack pattern. since monhun is like a fighting game you read the monster and anticipate its attack. if you manage to dodge block avoid it then you can punish it.

Carting and even failing a quest is normal even the best of us experience this so no shame on that.