During your trip to Rome/Civitavecchia, you can hire a car or use the public transportation system. Rome has an extensive public transportation system, and a 24-hour ticket for buses, trams, and metro costs €7 per day. Travel time can vary depending on traffic, but the distance between Rome and Civitavecchia is roughly 80 kilometers, which can take up to an hour by car, train or bus.
If you have more time to spare, visiting the Roman Forum or the Pantheon and the Trevi Fountain are also recommended. If you are visiting in the summer, make sure to stay hydrated, carry a water bottle, and wear comfortable shoes. If you have a shorter time, consider renting bikes or taking guided tours to cover more grounds. It's also a good idea to book reservations ahead of time to avoid waiting in long lines for popular tourist attractions.