When you have conversations with the local Norwegians, there will be those who want to speak English to you. There will be ones that will correct your Norwegian. Don't take offense by it. It's going to make you a better speaker of the language. Practice with anybody you can, because it's going to make you better in the language.
Norwegian language is in some ways similar to German. Some say it's a difficult language to learn. It seemed to come easy to me. It's a beautiful language, a lot of dialect differences between different parts of the country. So if you learn to speak in Oslo and you go to up north to Tromsø, you probably won't understand the people. It's similar to Danish and Swedish, probably more like Danish than Swedish, but if you can read one, you'll typically be able to read all three.
The language tip I have for you is go out and find some comic books. I used to like to use Calvin and Hobbes. It's called Tommy Otegren in Norway, and I liked it because it had a lot of slang terms and it helped me to learn the language a little bit faster. But that is my language tip for you. Go out and do it. I know that's not a popular way to do it, but it really did enhance my language and helped me to really get to a point where after about six months I could converse with people pretty fluently.