The movie was about Vikings that killed dragons to protect their home island. It was a lot different than the book.

Boys at about 10-12 go into dragon nursery caves during hibernation season and steal a baby. They are then to train them much like a falcon to hunt and fight.
Toothless is a small common gardener, terrier sized, green and no teeth until his baby teeth begin to grow.
Dragon watching is a sissy activity that Hiccup enjoyed. You are an idiot if you can read. Talking to dragons is bad. They are to just yell, loudly.
If they fail at the initiation then they will be kicked out of their tribe.