The nearest airport is Bremen, other Airports are Hamburg and Hannover. When traveling to these destinations, the best way forward is in many cases to buy a Deutschland-Ticket (58 Euro) from the Deutsche Bahn (https://int.bahn.de/en/offers/regional/deutschland-ticket?dbkanal_007=teaserBlock_2-1_button_Deutschlandticket), which can be used for any local trains and buses all over Germany for the entire period of your stay. In fact, it is valid for the month in which it is purchased. In this case, you do not need to buy any bus tickets in Oldenburg. Note that long distance trains (IC/ICE) are not included. 

Please use platforms such as Airbnb for accommodation. The most economic way would be to form groups of several people to share an apartment in Oldenburg. Note that booking early is recommended due to limited supply of (reasonably priced) accommodation as time goes by.

We highly recommend to check out the Youth Hostel for rooms (https://www.jugendherberge.de/en/youth-hostels/oldenburg/). They are relatively high priced, but very good value for money. Group rates could save some money.

 Another possibility is checking out the tourist information:
https://www.oldenburg.de/sprachversionen/gb/tourist-information/staying-overnight.html

Some hotels offer special rates for lecturers, if booked via the university. Please let us know, if you need a quote. The rooms can be paid directly at the hotel. Please observe cancellation policies.

There are perhaps possibilities to accommodate individuals privately, especially students, for a few nights, but we can give no guarantee whether that will work out well.