Steps to activate the Theme is in the Getting Started guide.
After theme activation you will see two messages: a welcome message with a button to the welcome screen (2) and the message recommended to install the plug-ins (1). Remember to use the context help, available via the Help tab on the top admin bar.
Push the button Welcome! (2)
You will find yourself on the Welcome screen, which shows the following installation steps.
You can find information on installing front page, here: Create a Small Business Website