how do i download movies and watch them with no internet

You should not need Internet access in order to watch a fully downloaded rental movie on the iPad. If the movies are purchased movies, there should be absolutely no problems at all since they will be stored on the device unless you decide to delete them.

You only needs internet if u just watch movie/show on the spot without purchase it but if bought it already this is already in ur folder and u just select movies what u want to see it but if u see a movie want to see without purchase then u need internet.

http://support.apple.com/kb/HT1491

You can go into the itunes App and purchase movies there.

Once fully downloaded onto your iPad they are fully watchable without an internet connection present.

They must be fully downloaded though.