Reykjavik is a walkable city, especially in the downtown area where most of the attractions are located. Taxis and buses are also available for those who prefer public transportation. A taxi from the airport to the city center costs around $100 and takes approximately 45 minutes.
If you have more time, consider visiting the Blue Lagoon or taking a Northern Lights tour. If you have less time, skip some of the museums and focus on exploring the city's colorful houses and vibrant street art. Remember to dress warmly and pack comfortable shoes as the weather in Reykjavik can be unpredictable and the streets can be slippery.