Do I have a separate seat if my party have a different reservation number?

Even if you make your own reservation, you can assign your seat through the web/mobile check-in from 24 hours prior to departure.

Even if you don't buy or assign your seat in advance, you will be able to get the seat you want at the airport check-in counter on that day if seats are available. However, depending on the pre-assigned seating situation, it may be difficult to allocate the desired seats.