I know the distance from me to my destination. I, also, know how many miles per hour, I'm going. How do I find out how long it would take me to get there.

You simply need to devide the distance by the speed to get the time, so: 600:50 = 12hrs

This is only if you drive the same speed rhe whole way and do not stop. If you stopped you need to add the delay to the time.

For example: if you delayed 20 min altogether you need to add 12:00+00:20 = 12:20.