It's best to explore Rome by foot or public transportation, which includes buses, trams, and the metro. A single ticket costs €1.50 and is valid for 100 minutes. A daily pass (24 hours) can be purchased for €7 and is valid for unlimited use on all public transportation. Consider purchasing a Roma Pass for €38 or €28 (depending on the validity period) to access monuments and museums with priority entry, as well as free public transportation during the validity period (2 days).
If you have more time, consider taking a day trip to the coastal town of Ostia Antica, which was once an important port city in ancient Rome. Alternatively, if you have less time, we suggest combining the Colosseum and Roman Forum, as the ticket is valid for two consecutive days, and visiting the Pantheon and Trevi Fountain at night for a more romantic atmosphere. Don't forget to wear comfortable shoes as there will be a lot of walking involved!