School/transition for teenager (Valencia)

My (Argentine) wife and I live in the US (Providence, RI) and we are considering moving to Valencia with our 14 year old son.
We met and lived in Barcelona for many years in the 90s and we have lived in Buenos Aires and other big cities.

We have lived here in Providence, a small city, in a neighborhood that is safe and beautiful since our son was born. But at 14 it is starting to feel boring for a kid with his personality. He is looking for a place with lots going on, lots of opportunity for friendship and activity and - very mportantly - not having to have parents driving you around to things, which is so common here in the US.

So, we are looking to come back to Spain (we have visited various places around the country many times) and Valencia is calling us, but we don’t know the city. I am retired so work is not a focus, but giving our son some great years through high school is a big priority for us

He speaks very good Spanish. It was his first language and to this day he speaks to my wife only in Spanish and on our annual visit to Argentina he integrates effortlessly into life, disappearing with family for days at a time (none of whom speak a word of English). One of his classes in his current school is a humanities class in Spanish only for kids from bilingual Spanish families.

That said, there is a huge difference between his level and what he would need in a Spanish secondary school (he would be 15 when we move to Valencia) He is currently in a very liberal/progressive private school, which he doesn’t love. He fantasizes about going to a public high school that is more urban ans mixed, with many more kids and less strict/less uptight. I went to those schools so I’m not sure he understands all the downsides, but the point is just that he isn’t very happy socially in a small, strict, privileged environment!

At a minimum I suppose we are hoping there is some place that is not too rigid, has a good number of kids his age to potentially find friends, and opportunity for sports (he is super into basketball).

After that very long introduction, my question is has anyone had a similar experience that would be helpful for us?

Any options on schools or other related advice MUCH appreciated.

Thank you!

Rich