If you are not logged in then click the login link, typically located down near the bottom of the sidebar.

If you are logged in then click the admin link, typically located down near the bottom of the sidebar where the login link used to be when you weren't logged in.

The terms 'admin' and 'admin area' and 'back office' are pretty much the same thing as each other.

jlsohio, after installation (going to /install/index.php on your blog) there it provides a link to the admin area and a random generated password (that you should change).

It sounds like you've missed that paragraph, so either go to your database and set the password in the evo_users table for user 'admin' by hand (phpMyAdmin for example), using MD5 to "encrypt" it or if you just think "huh?" edit /conf/_config.php and set $allow_evodb_reset to 1, go to /install/ again, un-install and re-install. After that, note the password and set $allow_evodb_reset to 0 again. You should also remove the /install/ folder from your webspace then.

Hope that helps..