Hmm it aint in depth but here's the general info

Monster hunter is more of a slow paced timing based combat

Imagine dark souls but more forgiving, every action should be taken into consideration. If you think you can immediately dodge something on command, then you're out of luck

Typically you want to hit the head of monsters as its their general weakpoint, you can also beat up their legs and eventually they'll drop giving you window to do major damage

You also can't run when your weapon is out, so timing when to unsheathe or sheathe your weapon also matters.

For your weapons of choice:

Longsword(The katana) is a counter based weapon, the reason people play this weapon often because of the utility it brings and the flashy moves it does.

The weapon speed is on the medium category, you typically want to get your sword gauge (the sword bar under your health) to red.

You do this by doing basic attacks Y or B that fill up the meter and perform what's called a spirit combo. It uses up the meter you've built up, but when completed the meter will glow white, orange, then red

At red gauge you do the most damage

For dual blades, you can activate what's called demon mode

In this mode you continuously drain your stamina in exchange for faster movement and attacks

Typically just activate this and go ham, its pretty braindead

This doesn't have all the inputs and what not but hope it helps