You can and should test your tap water just to get a fill of the test. Do not bother testing the CYA as there not be any.
Have you bought any CYA/Stabilizer yet? That and bleach are things you can and should go ahead and buy as you will need them right away!
Kim
I just tested my hose water. There's really no reading on the chlorine/bromine side and pH is off the chart high. That's all I've tested so far. Pool still isn't installed. Now I'm told they'll "get started" this afternoon.