There is no direct bus from the airport to Nallikari where your hotel is located. If you want to take a bus you'd have to take first a bus (8 or 9) to the centre and change there to bus 14 that has its final stop in front of the hotel. However, as it will be a Sunday, the buses run on a reduced schedule and thus you may have to wait for the connecting bus quite a while. The bus 9 runs from the airport once in an hour on Sundays always at 20 past the hour. The journey to town takes about 30 min to the City Hall bus stop and the bus 14 leaves from this same stop once in an hour always at quarter to the hour, so you'd have to wait 55 minutes in town. Timetables and ticket info are available at http://www.oulunjoukkoliikenne.fi/english .

A taxi to Nallikari will cost about 35 - 45 EUR and you can get one just outside the terminal, or you can order one in advance by calling +358 600 300 81 (there's a 7.10 EUR surcharge added onto the fare on the taxi meter for advance orders). If you order the taxi in advance, the driver will wait you in the arrivals hall with your name on a board or piece of paper. Further info on taxis: http://otaxi.fi/wpress/english/ .

There is also a low-cost taxi service Kyyti that you can order (and pay in advance) through their app. Further information: https://www.kyyti.com/english.html .