Click on the Servers button on the top right of the title bar to launch Apache and MySQL, they are your default GroupStart web and database servers. The launch status of the server is displayed on the left column in the Servers & Services section. A check mark next to the server/service indicates that this server/service will start/stop when the Servers button is pressed. The Apache web server (default web server) uses port 8888 by default. This port must be specified when calling the local web page in the browser, e.g.: http://localhost:8888
If you just upgraded from MAMP Free, you most likely have already made a website in your localhost. To create additional web sites you should create additional hosts. You should have one host in your host list for each web site you create.