Evidence that UFOs are real, and evidence that UFOs are not real.

Im writing a college research paper about extraterrestrial technology, but I’m having a hard time finding evidence from skeptics or why aliens aren’t here on Earth. Most of the articles are trying to prove that UFOs are real so I’m sort of stuck. I am looking for counter arguments on UFOs. Although, if you guys have evidence on why aliens and UFOs are real that would also be amazing. Teach me!