OK so scratch off most of your list.
Leave on the boots and eye pro.
Load up for a drive to Calgary or Edmonton or Red Deer for a shopping spree at airsoft stores and tac gear stores combined with a face to face with to get age verified at one of the spots.
Even if you don't buy and just nail your sizing it'll pay off in the long run. Consider also getting vetted for one of the AB forums too.
If you're getting a pistol get a secure hard shell holster, probably a RS one. The number of mags and whole pistols lost from sloppy soft holsters is unacceptable. Even with a hard holster consider a pistol lanyard.
If you're going AEG go LiPo or LiFe on the battery and get a proper charger.
Spend some time with the locals. If they're all in MC or woodland and you show up in an off spec pattern you'll be the guy who gets seen and shot first.
Think about how you'll carry water and other supplies on the field. Think about a radio. Think about a case for your rifle and pistol for transport.
When your verification tag goes live you'll see other used items on here for sale and you can find great deals on gear that doesn't wear out like charges or load bearing rigs.
Airsoft, where nothing is hurt but feelings.