Going by train from the airport takes about 30 minutes by the fast train to the main train station Termini in Rome. You can also choose regional trains that are cheaper than the fast train. The regional train takes longer and stops on more station than the fast train does. For us, choosing the regional trains was a better fit as we could stop to a station closer to our hotel than stopping at Termini.
If you know which station is closest to your hotel, you can find the journey easily with this link below. You will also find the price and timetable for your trip. To see the price of your trip, you need to enter your journey and number of people travelling.
Here you have the link to the Italian train company. On this webpage you can find local trains or from for example trains between Roma and Florence.
https://www.trenitalia.com/en.html
