I haven't traveled by air since before the pandemic, but prior to that, I was flying at least twice and sometimes three times a month by air. I use O2, and that's something you need to talk with your doc about,m because you may need O2 to fly. The cabins are pressurized between 6,000 and 8,000 feet, but that sometimes is even higher, so if you have any problems with altitude, you will want to have O2 with you. Las Vegas if at 2000 feet, so it's possible you may need O2 there as well. You can ask for a High Altitude Simulation Test to see whether you'll need O2 at altitude and how much

Even with O2, I never had a problem. I usually used a wheelchair, which may be harder to come by depending on where you are, but airports require a lot of walking, so it's worth it! If you arrive at the gate in a wheelchair, you can always board first, which has advantages; just get in line when they ask for people with disabilities. It helps when collecting luggage as well.