My superpower would be flight. I imagine being able to fly would make me feel free and nothing could weigh me down. Flight would also help me with traveling to everywhere I want to visit.
While flight would help with getting places faster, it is important to never crash. You don't have ultra-healing, only flight. So I would suggest staying above building level and try to avoid planes.
I think id also pick flight, it seems like itd be the most beneficial in a variety of situations- much more versatile than other powers like strength or x-ray vision.