We traveled with our 5.5 month old recently. I was EBF but read a lot about travel tips in general. Assuming you are flying with lo on your lap. If it's us travel or us airline you don't have to buckle baby to you anymore. It's part of the new FFA rules. If you are using the car seat it has to be the window seat. We did not buy a seat for lo but were lucky to get an empty seat on the return trip. It was nice to have our hands free! Otherwise the airline will gate check it for you and it's ready for you when you land. We bought a cover for the stroller at the airport for $15.
Feeding during takeoff and landing helped with air pressure and he slept through the 1.5 hour journey
When traveling with your baby You are permitted to carry breast milk and sealed baby food in quantities required for the journey only. TSA employees may ask you to taste/sample the 'liquid' and recommend carrying an empty container to pour some out if asked to. You can read about this on their website
As for pumping I found a website that indicates airports with nursing/family room facilities. I will try linking it here. I would also suggest a car adapter for the pump in case you plan on renting a car.
As for travel must haves: baby carrier, teether (necklace kind worked best for me)
We stayed at a hotel. Recommend setting up stations for diaper changes and a play area. Although for your 11 month old it may be difficult to restrict to one place! Carry a roll of duct tape for easy baby proofing.
Will add more if I remember anything...
https://www.tsa.gov/traveling-formula-breast-milk-and-juicetraveling-formula-breast-milk-and-juice
https://nursingrooms.wordpress.com