There are currently no default templates in Revo while it is in beta, not sure if there will be in GA the devs would be able to tell you that.
In order to create a template, you need to log in to the manager and then click on the elements tab above the resource tree on the left.
Then right click on the templates in the tree and select new template.
To create a template just use standard XHTML/CSS, to start off with just create on content area within the template and place [[*content]] where you want the content to appear.
So an example of the most basic template would be.
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
<meta http-equiv="Content-type" content="text/html; charset=utf-8" />
<title>[[++site_name]] - [[*pagetitle]]</title>
</head>
<body>
[[*content]]
</body>
</html>
Save the template
Then apply this template to your page by editing the page and in the Uses template box select the template you created.