City College New York is located in the Harlem section of Manhattan which is the northernmost area. It is situated between Amsterdam Avenue in the West and St Nicholas Avenue in the East and bordered in the north by 141th and in the south by 130rd Streets. It is easy to reach also: you can either take metro lines coming up Broadway (one Avenue further west than Amsterdam), or those that run underneath St. Nicholas Avenue. The latter means you need to climb up the terraces from 135th street station, or you go to 145th and then just walk back to 141st. Everything else is in walking distance around campus.
All information here: HowToGetThere