If you don't want to start creating a world from scratch you can start a server with a pre-made world. You can watch the video or read the written instructions below to achieve this task.
Begin by launching the Server Launcher.
This will open a new window that displays your current list of worlds installed from the world library.
If you are just starting out, your list might look pretty empty, let's install a new world. Start out by pressing the MinecraftEdu World Library button at the top. This will open a webpage to minecraftedu.com/worlds, the launcher will still maintain a small dialog box in the background.
When you've selected a world you wish to install, press the button located in the listing for the world.
This will activate the launcher that is in the background to download and install the world in the correct location automatically.
When completed, press Back to Server Launcher, and you will see the new world you've just installed listed as an option in your launcher.
This tells you a few things about the world you just installed, such as the name, age since last update and intended subject. Clicking the Details button will bring you back to the web listing in the World Library for that world. Pressing Browse Folder will open a Finder or Explorer window to the folder within your MinecraftEdu installation. To get started with your newly installed world, press Launch.
Connect to your server
Once your server has started, you will see the details about your specific world. Be sure to write down the ip address of the server so that others may connect with you. If you need to modify any of the player or world properties, you can do that from the server window or in-game with the teacher menu.
By pressing the World Information button, you can set some final settings for your world, such as the Message of the Day, and Welcome Message for users as they connect. This screen also tells you some basic information about your world.
Always remember to either save or back up your work before taking down the server!