how do i create in game characters,als,enemies, and animals

Questions & Answers
1

i also want to know how to make enemies attack your character and other players

2

To put all of that things you say about characters, enemies, animals and more there is something called import and export.

Here you can see what you can import into unity: http://unity3d.com/unity/editor/importing

Also, for enemies attack you may start to see this kind of videos to start: http://www.youtube.com/watch?v=fMUpJNndzcY and to know more about this is most in youtube and you can search for more about scripting in: http://unity3d.com/unity/features/scripting