Norway is the "it" place of Scandinavia, the wilderness, the landscape, the atmosphere, the clean air and water, everything will make you fall in love with it. Western Norway would be the most convenient place to go as it is the most well connected. Take a scenic train to Bergen, Geirangerfjord is a few hours away, Alesund is a beautiful place too(make sure to hike up to the Observatory), Flam is the showstopper with the legendary Flam railway being the crown jewel of your trip. Costs around 65 USD for return, but it's well worth, takes around 2 hours for a round trip.
The drawbacks of Norway, however, are food and expense. It's very expensive around, so opt for public transport as much as possible, eat cheap, stay low. And the food itself is not that great. However, you will not regret travelling there.
No as such, recently I've been on trek with my friends in himachal, name Thatharana trek so we camped there on the top of mountain but we hire guide who took 1200 just to show us the way and gather woods for night and water. Rest we were carrying on our own.
1. Do not litter plastic bottles and food covers
2. Carry two or three water bottles with you
3. Carry canned food
4. For bonfire, you might need permission in some areas as its restricted at Truind, only guides can tell you if you can do that or not Rest you're good to go!