Click above title - 'First Step - Download the Software' The page will reload. Follow the instructions to download the software.
To purchase click title Second Step - Buy First License above.
You are purchasing One Minecraft Education Edition License for one user which expires July Yearly (regardless of when you buy it). £7 per license. Start with one license and see how it works out for you and your family. There is the option to buy more if you need them.