One of the most popular ways to transfer from the airport is via the Leonardo Express train that takes you to Termini Station in the centre of the city. The train takes around 30 minutes to reach the city and costs €14 one-way. Keep in mind that it is quite a long walk from the baggage area to the train station at the airport, but trains are frequent. From Termini you can easily walk to your accommodation, catch a metro or a taxi. It is a busy station and pickpockets are very active, so be aware!
A more budget-friendly option is to take the bus to the city centre. Buses provided by Terravision are a popular option and cost around €6. The bus will drop you off at Termini Train Station. The journey takes between 40 minutes and an hour depending on traffic.
If you want comfort and convenience, taking a taxi is a good option. They can be found right outside the airport and will take you directly to your accommodation. The fare for destinations inside the Aurelian Walls is around €50, but make sure to travel with a registered Rome registered taxi. You can check this on the white label on the car door.