how many miles from amsterdam to dusseldorf
Amsterdam > Duesseldorf is around 140 miles, maybe 2.5 hours if you are lucky with traffic. If you are driving then googlemaps will give you route, route info and reasonably-accurate estimated timings.
If you want to travel by train look at the official Dutch international railway website:
Journey time is from 2h 19m on the direct (no change) trains.