I have a 2006 crown Victoria and I have a little bit of white smoke coming through my vents for about 10 seconds what could it be? When I had my ac on I heard a pop but no smoke. What could that be?

There may be several reasons for your issue. Check here for some of the most important: blower vents not switching
It could be an actuator(motor) that stopped working.

Here is a list of Crown Vic part:
List Blend Door Actuator 2003 Ford Crown Victoria Reilly Auto Parts

Here's an example of what may need to be done in a similar situation:
If you are handy, possibly buying a repair manual similar to this may help:

Hi Meliissa Ann,here's a link to your sensor. SAVE 20 GET 10 GIFT CARD ON ONLINE SHIP TO HOME ORDERS OF 100 OR MORE Here's a new part. http://www.autozone.com/engine-management/vehicle-transmission-speed-sensor/duralast-vehicle-transmission-speed-sensor/ford/crown-victoria/2006/8-cylinders-w-4-6l-sfi/631292_726013_2633

the smoke is probably coolant steam and the sweet smell is the unique aroma of engine coolant (anti-freeze). check the carpets, they may be wet with coolant. most likely a heater core failure.

Sounds like your heater core has a leak. try bypassing the heater core and then see what happens.

Relay switch

Your heater core has developed a leak (of coolant). The smell is the "sweet" smell of ethylene glycol,
a component of engine coolant. The white smoke is steam coming from the heated coolant evaporating.
The coolant is dripping into your duct work under the dashboard, and apparently being evaporated
out of the ductwork and sent into the passenger compartment, meaning its a small leak.
When the leak gets worse, you may get wet carpet on the front passenger side.

you should know this is easy problem , open up the control AC/blower device and melt with soldering all points over the circuit it's easy don't be scary

U either have a defective vacuum mode control switch (moves air to desired location) in ac control panel or loss of engine vacuum to ac control panel in dash.

Check the vaccum on the blend door

Could be an incorrect refrigerant charge or defective pressure switch causing the evaporator to freeze and the air flow over it is causing the ice to melt and the resulting white smoke is condensation