Lock Down Your Facebook User Account
If you created a Facebook account solely for the purpose of managing your school's page, you probably aren't interested in using Facebook on a personal level. If this is the case, below are steps to lock your account completely. You will still been "seen" on Facebook but nobody can see any of your activity and nobody can send you friend requests. If you don't do this, as soon as you create an account, Facebook will start suggesting you to people that it thinks might know you.
http://www.wikihow.com/Stop-All-Friend-Requests-on-Facebook
Another resource with more privacy settings:
http://facecrooks.com/Internet-Safety-Privacy/how-to-lockdown-your-facebook-account-for-maximum-privacy-and-security.html/
If you created an account and named it the name of the school or something that is not "you"...you will run the risk of Facebook deleting your account. It is against their policies to be anything other than "yourself". Your account will be deleted without any warning at all, and if you are the sole administrator of a page, the page will be deleted as well...without any warning, recourse, or chance to retrieve it.
Please note as well that Facebook does periodically change their privacy settings and in the past this has caused privacy settings to change. In order to maintain your privacy settings level, be sure to note any privacy update notifications that Facebook sends and manage your account accordingly.