Ryan Air is an affordable airline that offers regular flights to Oslo Torp. There is also a website called Sky Scanner that compares ticket prices from hundreds of airlines for the best deal.
I would catch a flight, as trains don't run from the US to Oslo...
The flight time from Oslo, Norway to London Heathrow Airport is about 1 hour, 27 minutes.
Cheap hotels in Oslo can be found on any hotel finder website. There are some great websites for this and you can find 5 star hotels that are decently cheap.
2hr 10min Dublin (DUB) to Oslo (OSL) by a nonstop flight operated by SAS - Scandinavian Airlines System.
About 5 hours.
About thee hours.
There are a number of options available for one to find information regarding cheap accommodations in Oslo. One can find information about the options on sites such as Visit Norway, Booking, Visit Oslo and Expedia.
About 21 and a half hours.
The flight time from John F. Kennedy International Airport to Oslo, Norway is: 7 hours, 52 minutes
About 8 hours.
A nonstop flight.
5 1/2 hours