Cotizao' is a colloquial, shortened form of "cotizado," which means "highly sought after" or "valued."
In the song, the artist boasts about having "el flow más cotizao'" (the most sought-after flow), indicating his style and presence are highly desirable and popular. It's an interesting word because it comes from the financial term "cotizar" (to quote or list on the stock market), but here it's used to describe social status and appeal, making it a clever piece of slang.
Voy pa' La calle is a night out song from Costa Rica. Dorian Ampie is heading into the street with his friends, feeling like the run has finally paid off and the money is coming in.
Most of the song is aimed at one woman. He tells her to call her friends, to stop hiding from her ex, and to come along for the drive down route 27. He is confident and a little boastful about it, and he does not pretend otherwise.
Underneath the bragging it is a simple invitation: leave the drama behind, get lost from everyone else for a night, and enjoy the party while it lasts.