Contemplating booking 4 domestic UA Y award tickets (family - 2 adults and 2 children) on AC ticket stock. I have *G via Copa - thank you internet. None of the other passengers have any status. Can book all 4 tickets on the same PNR or book separately.

Baggage allowance - just one piece for me and none for the others?
Lounge access - Assume can bring the whole family into United Club?
Other benefits - assume none?

Do I book via Aeroplan and then add copa number later?

Sorry for the newbie questions...