Seeing your very own UFO is an exciting experience, and a unique opportunity for you to add to the vast treasure of human knowledge. It is important that you properly handle the responsibility this opportunity gives you, so that all mankind can benefit from your experience.
The most important step is to gather evidence of your sighting, and this of course means getting the UFO on video. But since you have a video camera within reach and ready to use at all times, this step should be very easy. Don't have a video camera? That is rather unbelievable, but if it's actually true, then it is a shortcoming that you must correct immediately. After all, you can never win the grand prize on America's Funniest Home Videos if you don't have the equipment. Nor, for that matter, prove the existence of extraterrestrial intelligence. If, despite all good advice, you are still caught in the position of being without your video camera when the UFO appears, then your cell phone, which is surely video-capable, will have to do. It's not as good, but a cell phone video will still usually be acceptable as credible evidence. If you do not have a cell phone, you can stop reading now. The UFOs are not looking for you, and what you think you saw was probably just a balloon or an interesting cloud. Go about your business and forget it.
The next step is to give your evidence to credible authorities, so that it can be established as scientific fact and published. For your video, that of course means YouTube. YouTube is highly credible because it's so popular, and it's obvious it wouldn't be if it wasn't believable. Then of course you need to do your part to help people understand what they are seeing in your video. Have it analyzed by a UFO expert or researcher; you can find one with the help of YouTube, because they often post some of their other work there. Don't go to an astronomer, or an aviation expert, or a video analyst. You're dealing with a UFO, you need to consult with someone who knows about these things.
Now that you have provided your authenticated evidence of your UFO sighting, you may sit back and collect your just reward for the service you have done mankind. You may get your chance to be on TV (you can put that on YouTube also), and you will make many new and interesting friends. Naturally, your UFO will also inspire skepticism and disbelief, and perhaps some people will not be convinced. It's okay if that happens; questioning new discoveries is called science. Just remember, everyone thought the guys who invented bioresonance or the ones who discovered cold fusion were crackpots, too, and look what happened to them.
Oh, right. Well, you saw a UFO. That's different.