If you met someone online and you have both decided that it is time to meet up in person, the best location for a first date is a public place, just to be safe. Parks and restaurants are great places to meet up on the first date, especially if you do not know the person well.
If you are already close friends and have decided to start dating, the best place to go on a first date would be somewhere that you both find very special. Perhaps where you both realized that you were more than friends, or somewhere private enough so you can share a more intimate moment with one another.
Many people choose to go to a cinema for a first date but this is actually a hindrance when it comes to learning more about the other person. When two people go to watch a movie, they usually just sit next to each other until the movie is over and they just head to their individual homes. So in this case, a public place where it is relatively quiet enough for a proper conversation would be ideal.