its beautiful a lot of Portugal history in this reconstructed city ....
at night is really fun , a city that lives with a great intensity the academic life so, a lot of universities parties cool bars and discos open (some of them really expensive others that you pay 0,70€ for a beer).
food it's great and not rly expensive too, it depend on what you guys prefer ofc
people are really energetic , communicative ., you will party with groups of other ppl easily
search on airbnb prices for occupation.
if you're not renting a car , i recommend you 'bolt' app its the same as uber but you pay less also public transports are cheap and easy to understand.
if you're going , enjoyyy