1. Wander Around Strøget
The main street in Copenhagen with just about everything you could ask for as shopping, restaurants, bars, and so on. It's always crowded so it's popular.
It is a wonderful way to wander around the city without an agenda or a specific time frame. Pedestrian-only streets just make it so much more enjoyable and you can find anything for everyone with different price points along the way.
The street stretches almost two km starting from Nyhavn and ending at the main plaza, or the Tivoli Gardens amusement park. Even with a long stretch, you could hardly notice that tiring experience since everything seems to be a feast for the senses.