TwentyFourteen is a popular theme for school websites.
One feature that some people dislike is the way the site is displayed on a wide screen left aligned.
You can easily set the site to be entered like this if you like:
To do this you need to activate CSS editing in Dashboard -> Settings -> General.
This will add an extra menu item to the customiser.
In that section you can add this snippet of CSS to
.site { margin: 0 auto; }
More information on our CSS page