ultrasound tour in vegas?

hi! so i have general admission pit tickets for vegas! i’m from phoenix - so im traveling for this show and it’s my first time at this arena! has anyone been to this arena before for other shows? how early should i plan to get lined up to get barricade? or is barricade even the best view? I keep hearing about a “david” line where she walks through the crowd, and I also heard she spends more time towards the left side (stage right) i just need a lil help and some tips for a great experience! also have people had luck getting merch after the show or is it mostly sold out by then? and if anyone else is going to vegas-hi! it’s gonna be an amazing show <3