Copenhagen to Stockholm and archipelago

[Allfurcoatandnoknickers]

We've just booked for a couple of days in Copenhagen, then plan to get the train over to Stockholm. Booked a house in Ingaro, outside Stockholm next to a lake which looks beautiful, and is only 30 minutes outside Stockholm itself.
Firstly just wanted suggestions for two days in Copenhagen, then if anyone has any tips for train travel, and best things to do in Stockholm? We are a family of four, and 'kids' are 17 and 23 years old!!

We’ve done the train between Cph and Stockholm several times. It’s a direct train from Cph central station and you go through some nice countryside. Have your passports ready in case they check them in Malmø and I’d recommend booking your seat places in advance if you can.

Plenty to do in Cph so that really depends on what sort of things you like!

Both cities are good for walking around in and finding nice coffee shops, lots of museums and galleries etc.

In Stockholm Vasa museum and Skansen. We easily spent the day there in summer. Winter we got cold and were a bit ill so only managed half a day

Day in Skansen. Good 2-3 hours Vasa

Start with a canal trip in Copenhagen, it will give you a good feel for the place. Then choose a good museum- the design museum or the glyptoteket, plenty to choose from here copenhagencard.com/attractions
In the early evening, head to Tivoli for a walk around and rides.

The next day you could take the train to Roskilde- viking ship and cathedral, or maybe the train up to Helsingor where there is Kronborg castle.

The place famous for hippies is good
www.tripadvisor.co.uk/Attraction_Review-g189541-d259687-Reviews-Christiania-Copenhagen_Zealand.html
A church near by has a spiral staircase on the outside www.visitcopenhagen.com/copenhagen/planning/church-our-saviour-gdk410659