In the movie "THE FOURTH KIND" .... do u believe in the video evidence that are shown in the movie?

No. You seem to be confusing "evidence" and "footage". Dr. Abigail Tyler is played by Charlotte Milchard. Ashley Tyler is played by Mia McKenna-Bruce. The Fourth Kind is a fictional movie. Even if it says it is "based on real events", there is no compelling reason to believe that to be true. Even the Day of the Living Dead movies said they were based on real events... and I can't remember any zombie apocalypse recently, so that seems odd.