There are many different ways to redirect a page or a whole site to a new address. Here is a list of two of the most popular ways explained the simplest way possible. Most of these are different ways of doing the same thing, however some are useful for slightly different purposes.
Meta refresh (not suggested)
<meta http-equiv="refresh" content="1;url=http://yoururl.com/">
You will need to replace http://yoururl.com with your url, and the 1 with the number of seconds you wish the page to wait before redirecting. You will need to put it in the head of your html page.
Useful for: redirecting one page of your site to a new address.
.htaccess redirect one page (suggested)
Redirect 301 /oldpage.html http://www.example.com/newpage.html
Useful for: redirecting one page of your site to a new address
.htaccess redirect whole site (suggested)
Redirect 301 / http://www.example.com/
Useful for: redirecting whole website to a new address