for naples there are a lot of restaurants and pizzas delicious and they are never so expensive. Sorbillo is acclaimed as one of the best pizzas in the world, but in general its difficul to enter, theres always a lot of crowd and the policy is "no prenotations". 
Another restaurant you shouldnt miss is "Trattoria Da Nennella", its super delicious tipical popular food, they are famous for doing crazy things when the Naples soccer team wins something. 2 years ago they broke all the dishes to celebrate while people was eating their lunch😅
In general Naples is the craziest city in Italy and people are a lot characteristic and joyful.

Rome is the ethernal city, every place tells a story. You probably want to see the center from colosseum to pantheon, to Vatican city and Isola Tiberina. Also the Vatican Museum are really cool. The list of thibgs to see in Rome are really infinite...
You should absolutely eat carbonara and amatriciana, one of the best restaurant is "Tonnarello". Its in Trastevere, one of the most beautiful place where people go out in the night.
You should try the ice cream of "La Romana", its in 2-3 places in Rome. Its sososo good.

Bitcoin places and bitcoiners are not so much in Rome. Theres a shitcoin-themed bar, frankly avoidable.