Cabrón is a versatile and very common slang word in many Spanish-speaking countries, often used to mean "badass" or "awesome" in a casual context, but it can also be a strong expletive meaning "bastard" or "messed up" depending on the tone and context.
In this song, Nicky Jam uses it in two different ways. First, when he says "Diosito me dio la suerte, Ma', te convertiste en mi religión y estaría cabrón volver a comerte," it implies that it would be "badass" or incredibly amazing to be with her again. Later, when he mentions "Los recuerdos más cabrón los teníamos en el bote," he's referring to the most "intense" or "wild" memories they shared. It's a word that adds a raw, street-smart edge to the lyrics.
"Miami" is Nicky Jam looking back on a night with an old flame he can't get out of his head. He's with someone new now, and she's with someone else too, but he admits they're both still thinking of each other.
He keeps replaying the memory: her perfume left behind, a night on a boat by the sea, dancing to reggaeton. He tells her nothing has tasted the same since that night in Miami, and he wants her back even though she belongs to someone else now.
It's a song about a memory that won't fade and a longing for a version of the story where they end up together after all.