Read and listen to Norwegian as often as possible. Change the language of all your devices and apps to Norwegian. Find a native Norwegian to practice with on www.verbling.com (I don't know how many native Norwegians you can find there, but it's worth the try). Watch movies in Norwegian if possible. Watch Norwegian television programs: http://tv.nrk.no/programmer/utland
If you have any Norwegian-related questions or if you want me to correct your Norwegian (I am a native Norwegian), I'd be happy to help you in the forums on my own website as well: http://www.learnnorwegiannaturally.com/forums/
By the way, I would of course suggest you combine the activities mentioned in my previous comment with a structured course. A structured course will teach you the basics of the language, and thus help you benefit more from the "extracurricular" activities. The more fun activities (music, movies, video clips etc.) will keep you motivated as well as teach you the specific aspects of Norwegian that are relevant to your life and your interests. When I say a structured course, I mean that you could either get hold of a language learning book to follow step by step - or you could be participating in a class or getting some help from a professional teacher online. Lykke til.
If you are into music, movies, TV-series, documentaries, etc., then spend some time searching online for Norwegian music, films or TV-series in the genres you prefer listening to / watching, and perhaps also look for some Norwegian documentaries or short video clips online that deal with topics you are already interested in.
Like with any language, it will be more fun and efficient to learn Norwegian within a context that keeps you engaged and gives you something more than just pure knowledge about grammar rules and random vocabulary. If you read, watch and listen to things in Norwegian that you would otherwise spend time doing in your native language (because you select topics and activities that already interest you), you will learn vocabulary that is relevant to your particular interests and lifestyle.
So, I would suggest you look out for learning tools that will give you inspiration and keep you motivated. You could for instance try to memorize a song lyric if you discover a Norwegian song you particularly like listening to. You can get into a habit of regularly pause videos in order to mimic parts of the dialogue between the native speakers. Etc.
When you have learned some basic communication skills, it would of course be a good idea to try having a conversation with a native speaker. From that conversation you´ll most likely become aware of what you should focus on from there. And if you keep working on what you discover during your (regular) conversations with native speakers, you´ll learn quickly. The more you practice speaking, the faster you will learn.
Good luck :)