In order to find the P-Value, you need to determine the z-score and the area to the right (if positive) or left (if negative) of the standard normal for that z-score. If the hypothesis test is stating that H(a) does not equal 0, then you double the value (because it can go left or right of that score. If H(a) is greater than or equal to your value, than you only have to go that certain way and your p-value will most likely be a range.
You can't just plug values into a calculator and have it spit out your p-value.