where is the camshaft sensor at on the engine? is it hard to change ?

auto zone scan it said the code said a camshaft sensor

Just because Auto Zone said it was a camshaft sensor, doesn't mean the sensor is the fault.

It doesn't HAVE a camshaft sensor........Get the CORRECT code and post it .(It is listed as CMP/TDC sensor) Never seen any replaced. Check and make sure the sensor is plugged in correctly and the wires haven't been damaged by a belt. Sensor that they sold you is under the upper timing cover. Get a valve cover gasket too. Before you remove the valve cover (looks really easy to remove 'cause , well , it IS.) It's getting it back on AND not having oil puking out afterwards that is the fun part!! recommend air cleaner housing removal (don't forget the clamp underneath on throttle body and watch the direction of the rubber seal in it) then remove the bar behind the valve cover that the air cleaner bolts went into. That is the part that I've seen cause the most problems with getting the valve cover back on correctly. Most common problem area is around front corner by P/S bracket hard to see , but once it's running if it's not in right ............well you get the idea , I hope......Good luck.