Is there parking

No

No, the best way is the B41 or the museum subway station

There isnt a parking lot, but Flatbush between the Zoo and the library has parking. The metered part by the library is small so is usually full. The unmetered part is often taken up by people who have to move their car because of alternate side parking in their neighborhood. The street parking on Eastern Parkway is the same. So, as Betsy said more succinctly, in all practicality there isn't parking. The B41 stops right at the library and the Brooklyn Museum 2/3 stop is a pleasant one block walk away along tree lined Eastern Parkway.