First time mama and we flew with our daughter when she was about 6 months old. I was also exclusively pumping every 3-4 hours and she had 2-3 naps a day scheduled at the time. So we decided to base our flight times on those specifics to keep her naps and feeding schedule as close as possible).
Baby’s brain will still be on whatever schedule you have them on in your time zone, I’d try to schedule the flight during their nap if you can. In my experience, my kiddo has never slept on night time flights (flown at 2mo, 6mo, 9mo, 15mo, etc), but she will sleep on flights during nap time.
When my daughter was little, I tried to take flights at night. She could be up or fall asleep as I wore her on my chest through the airport and then once we were seated and she’d latch she’d go to bed. When we landed and got to family house she might wake up & that’s fine to see people or she’d sleep through with the car ride and what not anyways