The phenomenon may correspond to flying machines; if you understand Spanish, this is good, from a late practicing psychiatrist in Madrid, Spain:
View: https://youtu.be/aYhwNLixAGA
but there may be many different technologies and origins in objects watched, also in intentions, the proposal that you won't meet them until having developed the technology for interstellar travel is reasonable.
Some 'contacted' reported from it: 'We are in good will, but there are others', and 'Some of them, if we met them, we destroy them'
The Roswell incident, involving Mantell Mustang P-51 and an unidentified flying thing, was described in some reports as metal sheet in debris of P-51 containing many tiny holes; decades later, SciAm published about experimental 'Particle Beam Weapons' having same effect.
Well, some people pass time in watching airliners in airports, taking images of it. Nice!
For now, you won't go any further in UFO sighting, but if you have a pilot's license, you can do more with airliners than watching it. Bless you +