Sorry for the double post but i feel like a post with general tips for going to copenhagen warrants its own post.
Denmark for the most part and especially copenhagen is almost entirely cashless. I genuinely cannot remember the last time i used cash. Make sure your card works before you go or your journey will be hell. Generally visa debit/credit works everywhere. Mastercard is probably fine but its not as widely accepted as visa.
Check the forecast before you go. This year in april we went from snow to rain to sunshine in 2 hours. Literally anything can happen during the danish "spring". Just make sure you dont decide to pack the cold weather clothes when it suddenly turns out to be 25 degrees and sunny the whole week like last time. No matter what, BRING A RAINCOAT. Sure, umbrellas exist, but copenhagen is quite close to the sea and the whole country is a fucking wind tunnel so an umbrella is almost always entirely useless.
Google maps works just fine when it comes to navigating the city both on foot and on public transport. Unless youre already used to cycling in a city and are familiar with the prerequisite hand signals i would avoid navigating copenhagen by bike despite the romantic notion that its a bike friendly city. I guess this doubles as a reminder to make sure you remember to check the bike lanes before you cross the road, not only the actual road. Angry danish commuters are scary.
The app DOT Tickets on your phone is great because it lets you buy public transport tickets directly on your phone instead of having to fuck around with ticketing machines. All public transport runs on the same ticket system and google maps should let you know how big your ticket needs to be.
Once again remember to check out food and other sights in copenhagen. You can see pretty much everything touristy in an afternoon if youre quick.