Nevada only honors Nevada permits. You can apply to Metro for an out of state permit...but it's at least a 120-day (don't hold your breath) wait.
You'd need to go to LV, get training, qualify with your sidearm, take a written exam and then go to the PD and complete the process.
You also need to register your guns with the LVMPD within 24 hours of your arrival in Clark County.
Washoe county is faster, but you still have to register the firearms (blue card) when you enter Las Vegas.
Technically, open carry isn't illegal in Clark County (or most of the state), but I wouldn't recommend it on the strip unless you want to know what 128 degree asphalt tastes like.
MP