score:2
Starting with the last question first, whether your phone will work on Norwegian carriers will depend on
You can check the first with your carrier in Canada and the wiki link above should have enough information.
As for plans, you will probably want to just get a prepaid SIM. This is quite a bit more common in Europe than North America, and you might not be able to get a post-paid account right away anyway. (Starting and stopping contracts is more difficult generally.)
According to this page, Norway has a number of prepaid options that should do what you want, and you can buy/recharge them any kiosk.
As the other answer mentioned, for short trips, the cost should be reasonable. If you want to use more data or stay a longer time in other countries, the usual thing would be to just buy a SIM card there.
Upvote:-1
I would recommend myself that you try https://mycall.no/ these are both prepaid cards and plans, MyCall's entire gimmick is that you can cheaply call the entire World/Europe from Norway/to Norway etc..
You can "top up" your prepaid card online also.
Upvote:2
The official travel guide, visitnorway.com has a useful page on using mobile phones in Norway, with a list of all the local operators and some tips on where to buy a SIM card. You could use that as a starting point to find out exactly what's on offer in Norway.
Just about any monthly plan or prepaid/pay-as-you-go offer in Norway should include roaming (perhaps after activating it online) and there is no reason you could not use them elsewhere in Europe. If I am not mistaken, you will however need to make sure to get a micro SIM for your Galaxy S4, which operators might not all offer by default. And of course, you will also need to ensure your current phone is not locked by your Canadian operator.
While Norway is not a full EU member, I think it is covered by the EU roaming price caps. Data is still expensive but receiving SMS in any EU country should be free and sending them relatively cheap (€0.07/NOK 0.59 on top of the price of a local SMS), even on the most basic prepaid card. So if you and your friends all have a Norwegian plan with unlimited text messages, you could chat abroad for €0.07 per message.
That should cover short trips to France, Italy, Spain or Greece but Turkey (or Switzerland and most of South-Eastern Europe, if you happen to go there on the way) are not included so you could have to pay more when using a Norwegian (or other EU-based) SIM card there. Alternatively, if you are staying a little longer or want more than a few SMS, buying a local SIM card is usually the cheapest option, if you don't mind the hassle.