There are a number of exceptions in the current federal gun free school zone law. Here are a few: If you are on private property.
If you are in a vehicle passing through, and the gun is unloaded and in a locked case.
If you have a permit to carry the gun, issued from the state you are in.
If you are hired by the school and have permission from them.
So as soon as you step off of your property you have to have your firearm unloaded and in a locked case (useless) unless you get that state government issued permission to exercise your 2nd amendment rights.
Have to wonder what effect this would have on the state granted "full reicprocity rights" of non-residents who do have a locally recognized permit from their home state.