How do I get a different weapon?
Um, I don't know what is available in the demo, but you should have the basic level one versions of all of the different types of weapons. Go to one of the chests in the main city and select "change equipment," then highlight the weapon and switch to whatever you want.
Dual blades are probably the best for a newbie, it's the weapon that most closely resembles that of other third-person action games. They're fast, you don't have to be thinking on an individual button input to succeed, etc.
Stop right there and uninstall. MHW is not the game for you.
I think that's a little harsh, it just requires an attitude adjustment from prior games. I think the biggest change from other games is that you need to really think out and commit to every button input you make. You need pretty good timing to make a hit and each of your options has different damage, wind-up times, and recovery times. It's totally foreign if you're used to Bayonetta but once you've got it it's really rewarding. So once you're done with the dual blades, Roy, maybe move on to either the Great Sword or Hammer, both of which are slow, hard hitting weapons that really reward picking your spots (while not necessarily being ery complicated combo-wise).
I don't think MHW would have been successful if it weren't for Dark Souls teaching western gamers how to do this kind of deliberate combat.
