While walking is an option for getting around Akureyri, renting a car or taking a taxi may be a more comfortable way to explore the area. Expect to spend around ISK 5000 for round-trip transportation to Goðafoss waterfall.
If you have more time, consider visiting the Akureyri Art Museum, the Hof Cultural and Conference Centre, or taking a whale watching tour. If your time is limited, consider skipping the food tour or the Arctic Botanical Gardens.