AUTHORS ONLY, HAVE ANOTHER QUESTION?

Okay, If I'm doing research for my story, am I allowed to put the real things in my story? For example: Wal-Mart, the name of a real high school in a real place, and the name of real famous person like Paula Abdul? Do I have to get permission, or just put them in the story without having to ask? I would love to know, It took me a really long time to do research for a very short scene and I would like to not waste so much time if it is not allowed. If it is, then what do I have to do to actually put the information in the book? Thanks So Much!