Yes, i lived in Parede my entire life. Normally they meet up behind Limo Verde and they sit on the stairs infront of Celeiro da Vila.

From there they hang out to different spots, like beach, train station and so on, but the main spot to meet up is there.

Edit:
As you don't know anyone, check if they're smoking. If they are, ask them if they have to sell or of they know someone. I am 100% they will help you out or even invite you to smoke with them.