Does the Nikon D5100 have a timer?

I want to get a D5100 and was wondering if it has a time so if I take a picture I can get I place and then it takes a picture. And if it can, please tell me how.

Yes, it does. Read the manual.

Most cameras in this price range have a self-timer. The timer is located in the camera's "menu". And on better cameras gives you the option of using one of two times like i.e. 10 seconds or 20 seconds.

You should also be able to locate this information in your instruction manual.

Yes and set the auto-focus to continuous if you want to be in focus when the shutter goes off.