Hello! Newbie around these parts, learning a lot, lot to learn.

I'm attempting to book 3 EK first class seats for next year. I'm doing a live search on seats.aero, and see availability for 3 passengers on the date I'm looking for. When I check Emirates directly, I see availability for 1 passenger but not 3. I checked expertflyer and see availability for 4 passengers in F and A, but nothing pulls up for Z. I think I've reached the end of my sleuthing capability. Is it possible that Emirates will only let me book one first class ticket at a time? In other words, can I book three separate tickets for the 3 passengers? I worry that I will only be able to book for one passenger and not the others (there is also no availability in O for that date). Would love for input. Please be kind, I'm probably doing many things wrong while trying to learn!