NC Grateful Dead Dad

Taking my first cruise in over 30 years. Taking it with the fam- wife who has a European cruise under her belt, and the kids (20 & 18) who have never cruised.

Going on Symphony in August. Leaving out of Civitavecchia, Italy that night at 8:00. We are staying in Rome the night before and were going to arrange for a ride to Civitavecchia and would like to book it. Or since it is an hour and a half away, do we need to book a room in Civitavecchia instead? For an 8pm departure, what will be the earliest non-suite passangers will be able to start boarding?