If you’re looking at the neighborhoods around Citi Field, warning, definitely stay away from the area to the east of the stadium, Seaver Avenue, 34th and 35th Avenue, and Willets Pt. Blvd. It’s a run down area partly under demolition: Willets Point Queens Iron Triangle auto body shops: New York City neighorhood.
Willets Point, Queens: exploring the industrial NYC area, in photos - Curbed NY
On the other hand, the tennis stadium where the US Open is held is a 10 minute walk from Citi Field. The official name is the USTA Billie Jean King National Tennis Center. And 5 minutes further is the Unisphere: Flushing Meadows Corona Park Highlights - Unisphere : NYC Parks