Very easy to get anywhere you want from here. Metro, buses, trams, flybuss.
You can also just walk to many interesting places. Munch museum, Botanical garden are just 15 walk/1 metro station away. 15 walking to trendy bohemian Grunerløkka to get a lot of inspiration and experience Oslo in a unique way.
Oslo Sentral station, Opera, Rådhusplassen, Karl Johan street is just 10-15 min away by bus/metro/tram, or 30 min walking down the hill.