It's Like This, Cat by Emily Neville

"Superb. The best junior novel I've ever read about big-city life." - The New York Times.
After another fight with Pop, 14-year-old Dave storms out of their apartment and nearly gets hit by a car. Kate, the local cat lady, comes to the rescue, and Dave returns home with an ally: Cat, the stray tom that becomes Dave's confidante and his key to new friendships and experiences. Cat inadvertently leads Dave to Tom, a troubled 19-year-old who needs help, and Mary, a shy girl who opens Dave's eyes and ears to music and theater. Even the Cat-related confrontations with Pop take on a new spirit, with less shouting and more understanding.
It's Like This, Cat offers a vivid tour of New York City in the 1960s. From the genteel environs of Gramercy Park to a bohemian corner of Coney Island, the atmospheric journey is punctuated by stickball games, pastrami sandwiches, and a ride on the Staten Island Ferry. Recounted with humor, a remarkably realistic teenage voice, and Emil Weiss's pitch-perfect illustrations, this 1964 Newbery Award-winning tale recaptures the excitement and challenges of growing up in the big city.