From Rome to Sorrento, it takes about 3 hours (245 km).
Take the motorway direction Naples then follow direction Penisola Sorrentina, when you arrive in Castellamare (the exit after Pompei) follow always direction Sorrento.
Just before the entrance of Sorrento, you will see on the left side up on the hill Hotel Cristina.
It might be more relaxing to come to the Sorrento area NOT BY CAR.
From Rome, take the train Rome – Naples.
From the train station in Naples take the train (Circumvesuviana line) that runs frequently (approximately every 30 minutes from 5:00 to 22:30) from Naples to Sorrento.
It takes about one hour, the cost is about € 3,50 per person.
From Rome you can take Marozzi bus that leaves from Roma Stazione Tiburtina at 15:00 (only on working days) and arrives in Sorrento at 18:45, the cost is € 15,50 per person (there is also a bus leaving at 7:00 a.m. only on Friday, Saturday and Sunday).
From Naples airport to Sorrento there is also Curreri shuttle bus services, it takes about one hour the cost is about € 10 per person.