Practical guide for participants at “Geometry and analysis of quantum groups”
You can find travel restrictions to Norway here. Oslo Gardermoen Airport (IATA: OSL) is the main airport for Oslo. This entry in Wikitravel gives a good overview of the connections to the city from the airport. Another option is Sandefjord Airport (IATA: TRF), but it has fewer connections to the city.
Reisekort (Travelcard) is the most convenient way to get around in the city. This is valid on T-bane (metro), bus, tram, commuter train, and non-sightseeing boat lines operated by Ruter, and you can either charge it for pay-as-you-go or for period tickets (24-hour ticket is 114NOK and 7-day ticket is 320NOK). Other than traveling from and to the airport, Zone 1 should be enough.
Standard mobile mapping services already cover the public transportation in Oslo quite well, but Ruter also has their own mobile app Ruter.
The winter school will happen on Blindern campus of University of Oslo. The campus is close to Blindern station (metro) and Universitetet Blindern stop (tram).
Inside Blindern campus
There are several canteens and cafes in the campus, but many of them will be on summer break during the summerschool / workshop. See this page (filter for UiO Blindern) for opening hours, but here are some standard choices:
Like other Scandinavian countries, Norway has its own currency, Norwegian Krone. However, practically any business accepts credit cards, so usually you do not have to carry large amount of cash. ATMs are called minibanks.