Rome tips please

[Freshstarts23]

Travelling to Rome soon, only staying 2 nights. Have booked the colosseum and will visit the trevi fountainbut that’s all so far. Don’t really want to book anything else that costs much.
Have a few questions if anyone is kind enough to answer..

1. Do we need some kind of travel cards for buses and underground or can we use contactless like in London?
2. Any recommendations of places to eat? Nothing too fancy.
3. Any places to see, nice places to walk, must see’s etc.
4. How easy is travel to and from the airport.

Thank you @HappiDaze

Here's a map of where all the free water fountains are to fill up your bottle. Rome is hot and it will save you a fortune! https://goo.gl/maps/tkWJDzKJJ8qMbWcW8

The panoramic glass lift which takes you to the top of the Monument to Vittorio Emmanuel is an absolute must-do. The building itself is mindblowing but the views of Rome from the top are amazing. Afterwards we sat outside one of the pavement cafes on the Piazza Venezia where we watched the whole building light up after dark. Beautiful!