G'Day Newflyer,
wing incidence is the angle the wing against the centre thrust that will cut through the wind. It will affect how the plane flies overall. You may want to speak to a fellow club member about borrowing an incidence meter of some type so you can get that part correct.
T-Pins are merely pins to hold down the wood to the building board. Normally you would place wax paper over the plane and pin the wood through that.
The Pete N Poke might be a sometimes daunting first build. Certainly post questions here but you may want to seek some first hand assistance with someone at your club.
Keep us posted
Bob aka Nuker