I want people to be able to subscribe to newsletters that I create/ I also want them to have their own accounts, and be able to blog. How in the world can I create something like this? Can you please point me in the right direction?

Design your site. The look, the feel, etc.
Script it out, load the documents on your webserver.
Incorporate a Content Management System (Drupal for example) to handle account creation, and newsletter distribution.
Set Up a (mySQL) database to store account info and news letters.