Log in with your new password, and you're basically ready to go.
If you click anywhere in the center of the page you should see an editing toolbar appear. More on how to use this in a separate session, but basically that's you up and running.
The Mara Toolbar at top of screen should have changed to a dropdown menu. There aren't all that many items on the top menu, and that's because Mara works mostly by using interactive tools, working on the page itself. Those that are present should be self explanatory. As of v7 if you are logged on, pages are automatically opened in editing mode. It was found that this saves a little time and effort since it's mostly what you want.
Note that some features are intentionally turned off when in edit mode, for example you won't see contact forms or galleries. Instead, you will see a red placeholder. This is so that you don't inadvertently change the code that makes the feature work.
Here we are editing this page. Just before I added the text, 'Here we are editing this page.' ;-)
Anyway, that's the install process completed. In practice, it takes a lot less time to do than to describe. Worth noting that the CPanel part is basically similar for any CMS that you want to install from a download. It's a better method than using FTP to upload the individual files, which tends to be very slow by comparison.