Most of the attractions are within walking distance or accessible via tram, which costs around AUD 4.50 for a two-hour Myki ticket. A taxi from the airport to the city centre costs around AUD 60-70 and takes approximately 30 minutes.
If you have more time, consider taking a day trip to the Great Ocean Road or the Phillip Island Penguin Parade. For a shorter stay, skip the Lane Ways Tour or the Queen Victoria Market. Don't forget to try some of Melbourne's best coffee and brunch spots, such as Proud Mary and Hardware Societe.