What is it like living in Sweden?

Alright, well to start off I'm a seventeen year old American and moving to Sweden next year with my family. I've never visited Sweden so I've asked my mom how it's like since she used to live there, but that was in the 80's so I'm sure the Sweden she remembers is a little different now haha. Most of these questions are for guys and girls around my age and a bit older to answer, but I appreciate all answers. :) What's the weather like? Are the shops there expensive? How is the nightlife? (If you live there) Is it nice living in Malmö? If not, why? (If you live there) Is it nice living in Gothenburg? If not, why? Where would you recommend I live? How is the public transportation? What's your opinion on Americans? Have you ever met an American teenager? A lot of people say Swedes are very shy, do you think it's true? Is there any rules of Swedish etiquette to follow? Sorry if this was too long or the questions weren't easy to answer. Thanks in advance!