I uploaded new and updated files and they are not showing up on the internet. Why?
Your browser keeps a cache and most likely you are looking at copies in your cache. With Firefox you can press Ctrl-R (or View -> Reload) and in Internet Explorer you can press F5.
Customer since 2000 openvein.org
And be sure to upload to the correct directory - named like your domain.
And you may need to remove the index.html file that might be there already.
And you may need to wait some hours for DNS to change, if you have just moved to DH.
Should my files all be on the new server already or do I have to put them there?
What new server? If they moved you to a new server here, be sure you FTP to example.com, and not machine.dreamhost.com.