Everything I read is timing when they were hungry. My 15th month still breastfed every 4 hours and pushed till 5. So I waited when I knew we were getting on the plane. Before takeoff is when I fed her and covered her ears so she wasn’t scared of the sound till we were stabilized in the air and uncovered her ears so they’d “pop” with the pressure from them drinking instead of them being uncomfortable since babies can’t pop their ears up in the air.
Take lots of favorite snacks and a new non-noisy toy that you can give at take off. This will hopefully distract for your little one to not notice the ears popping.
Most airlines will let you take the stroller right to the plane and check it there. You’ll probably have to baggage check the pack and play.
Put some cotton in the ears before take-off and before landing, it wil minimize the amount of pressure in the ears for her and then she would not be so fussy due to uncomfortable ears…
You can’t take a playpin on the flight…
Went to doctor and asked for my 15 month old and he said give her some Benadryl 15 minutes before take off to let her sleep! It worked!
Toys and snacks. Try to fly during a time she’s usually tired so she can sleep.
And good lord, better have a mask on her.
You can check your stroller at the gate and keep it until your boarding. I just traveled with my 13 month old. Encourage them to drink or eat a snack while taking off to help with the ears (mine still had a nuk at the time and she just used that to help). Keep a quiet toy - mine loves pop its so we had a couple of those. And she would watch a show on my phone (low volume). It was a great flight both ways with her. Try to change the diaper (or if potty trained try to encourage going potty right before boarding).
My son is 2 and we went on his first trip in December. Depending what airline you use, they will throw the stroller and car seat for free. You can use the stroller up until you board. His diaper bag was also free to take on and I got to take snacks and juice for him. Specifically took some chewy fruit snacks for the ear popping which surprisingly didn’t bother him. I took his Nintendo ds and some coloring books. If you could time a nap with the flight that always works, but my son ended up falling asleep. Make sure to feed and change before boarding but I did have to change him during the flight and most bathrooms have changing tables.
I check in at the gate and board last. Making a toddler sit longer than everyone else is just asking for trouble. Also, if you happen to have an empty seat in your row then use your car seat. Assuming you aren’t paying for a seat.
Under 2 can technically be a “lap child,” which you don’t have to pay for a ticket. It really depends on your child and what time/how long the flight is, but if they are pretty active and the flight is not during nap or sleep time, it would be worth it to pay for their own seat. It can be very tight quarters having an older lap child especially for a longer flight. At least with their own seat they can stretch out, stand up, etc. (except during take off/landing)
Bring plenty of snacks and quiet toys/books to switch out and keep them occupied. Also a luvie/blanket to cuddle. I’d suggest giving her the window seat so she can look out. Tablet with a few downloaded shows works great if you allow that.
Stroller you can gate check (keep it with you throughout the airport, leave it as you board, and it’ll be waiting for you as you deplane). Pack n play will need to be checked with your luggage. Car seats are free to check with your luggage (as are strollers if you’d prefer to do that).
I’d see if there’s anyone your husband’s friend can borrow a pack n play from locally as stuff can get pretty beat up in the luggage compartment.
Most of all make it fun for your little, if you’re stressed they’ll be stressed!
Both of my kids were 9 months for their first flights. We had to check the stroller at the gate before getting on the plane but it was waiting for us at the gate when we got off. We just made sure we had bottles, snacks and toys. When taking off and landing, they had their bottles and were fine. For a toddler I’d just suggest packing stuff to keep them occupied.
I always took chuppa chups for the kids to suck on take off and landing for their ears.
It’s probably cheaper to buy a new pack n play there than check one lol.
Bottle or soother during take off and landing? If still using… or something to chew/gnaw on…relax… babies can feel your tension… so… create less for you by being well prepared and looked after, yourself. Well rested, fed, prepared, early, enjoy!!! Have books and small toys to play with
May be easier to ask friends that live there if they have one or if they could check their local buy nothing so you could have it there and not have to travel with those items.
My daughter screamed the whole 3 hours we were on the plane to Vegas. It was terrible. I couldn’t get her to take her cup for lift off or landing. She fell asleep literally 30 mins before we landed. Ngl. That SUCKED. So I’m definitely waiting to get on a plane with her again 
Check the car seat. Pack n play counts as a bag for most airlines. Check stroller at each gate when boarding. Pack lots of snacks and get water for sippy cup after you get through security.
The less you bring on the plane, the better. JUST REMEMBER the agony isn’t forever. Lol.
You check the stroller and pack and play. You don’t take them in the cabin.
Buy a stroller small enough that you don’t have to put in the hold and can take on as hand luggage
Check the stroller at the gate for free. Buy a cheap pack and play once you’re there. DO NOT check the carseat.
Strollers and carseats fly free under the plain.
Adult dosage of Benadryl 
Do not check your stroller like baggage. You can check it at the gate for free with most airlines, just double check. I would just do an umbrella stroller since it’s a little less bulky. Pack snacks, bring a sippy cup. And bring a blanket. We flew super early and my 2 year old passed out during the whole flight (4 hours).
I personally wouldn’t take a pack n play, sounds like a headache. Borrow one from a friend if you can.
Don’t check your seat, take it on the plane and buy them a seat.
I’ve flown way to many times with small children, my oldest two are 15mo apart, you are definitely going to get stares and eye rolls. The last time I made cute little bags with a paper explaining that I (my daughter’s) was sorry if I get upset, with a couple pieces of candy. I also brought earplugs for people around us just in case( we were flying out of Vegas to Chicago) people are pretty understanding. Also depending on who you fly with ( southwest for us) you get to pick your seats. People who are annoyed with kids will steer away from the surrounding seats. With that, music with kids headphones are a lifesaver!!!
Lots and lots of snacks
Bottle or sippy cup at least. When your ears pop kiddos get freaked out so I had a bottle ready for take off and landing and didn’t hear a peep.
Rent a stroller/Pack n Play once you reach your destination. Airliners usually charge $40 for each upon boarding plane.
I am not sure about the pack n’ play however the stroller you should be able to check in for free at the gate and they will take it down and store it for you during the flight and bring it back up for you after the flight. Several years ago when I was pregnant I flew with my at the time 6-year-old, 8 month old and I was also pregnant and I was able to do that with the stroller. The pack n’ play you may have to check in I don’t believe you can carry the pack n’ play on. I would definitely recommend bringing some small toys snacks and probably a tablet or something that she can watch movies on. A small blanket may also be helpful because sometimes planes can get cold.
Take ear plugs (lots) to pass out to passengers just in case the pressure hurts your kiddos ears… I was able to take 5oz of formula in a bottle and gave it to my little one when we took off and then when we were landing to help her ears “pop”… hope this helps!