This Bookstore has an amazing photography section. I go here to get inspired. You can spend hours in here looking at all kinds of great photography books.
I think it takes place every Saturday morning to afternoon, vintage shopping while having a great view at the Manhattan skyline from the East River State park. You will find lots of vintage shops and warehouses around this area of Williamsburg.
Joseph Leonard is one of my favorite cozy spots for brunch on the weekend. After a long week of work their avocado toast and a bloody mary hits the spot. Get there early or expect to wait, it's small and limited seating. Their sister restaurant Jeffreys Grocery across the street is also very good, but no expresso drinks which and I need my morning latte.