Neither of those actually answer his questions there...
For train routes, best bet is Deustche Bahn's official site... Should be able to input everything and get lots of information... Continental train services are far superior to the UK, and I think the trip is relatively simple and involves two trains, but I've never done it, but some on here have...
There should be links to shuttle information on the Europa website... Probably in their directions tab... When I used one it was €100 EACH WAY, this might have changed but I doubt it somehow...
All info (and shuttle links) are at http://www.europapark.de/en/services-info/worth-knowing/getting-here