Al or del

Al or del
 

How did I do? As far as I understand.... al is more like "to the" and "del" is more like "of the"...

Fracia está al norte de España
El agua del mar no es portable
Voy al cine todos los fines de semana. (I'm going to the cinema every weekend?)
El abrigo del muchacho era gris.
Me habló del libro que había
Recibió la noticia al día siguiente
Tenemos que tratar al problema de la juventud (I don't understand how to translate it...something like "we have a problem....youth")
He dejado mi coche al lado del tuyo (My translation doesn't make sense here as well: I will leave my car on this side of you)
Vengo al dentista
Los hombres al sur son morenos

It's "tratar el problema" not "tratar al problema".
I'd translate it like: We have to deal with the problem of the youth.

I left my car near yours


Don't rely on my corrections though. Let's see what others have to say.