Most of the attractions on this itinerary are centrally located and can be easily accessed on foot. Alternatively, you can also make use of the metro, buses or taxis for longer distances. Rome's public transport system is highly-efficient and economical. A one-day pass for public transport costs €7 and can be bought online or at any metro station.
If you have more time, consider visiting the Roman Forum or the Capitoline Hill. If you have less time, you can skip the Vatican Museum and the Pantheon. For food, do not miss out on trying the famous Roman Pizza or the Tiramisu. Lastly, make sure to carry a water bottle with you and wear comfortable shoes for the walking-heavy itinerary.