did they use any call signs?
Yes, "Gumdrop", "Spider" etc.
Apollo 9
After the Gemini 3 craft was dubbed "Molly Brown" by Grissom, NASA forbade naming spacecraft. The fact that during the Apollo9 mission, the CSM and LM would separate and need different call signs caused the Apollo9 astronauts to push for a change. In simulations, they began to refer to the CSM as "Gumdrop", a name inspired by the CM's appearance while in the blue protective wrapping in which it was transported from the manufacturer, and the LM as "Spider", inspired by the LM's appearance with landing legs deployed. Personnel in NASA public relations thought the names were too informal, but the call signs ultimately gained official sanction. NASA required more formal call signs for future missions, starting with Apollo 11.
what is apollo 9? It was a human spaceflight, the third in NASA's Apollo program. who were the crew members? McDivitt, Scott, and Schweickart
wiki:1558688
Apollo 9 [SEP] Spacecraft, equipment and call signs
Apollo9 used CSM-104, the third block II CSM to be flown with astronauts aboard. Apollo 8, lacking a lunar module, did not have docking equipment; Apollo9 flew the probe-and-drogue assembly used for docking along with other equipment added near the forward hatch of the CM; this allowed for rigid docking of the two craft, and for internal transfer between CM and LM. Had the switch in missions between Apollo8 and9 not occurred, the Earth-orbit mission would have flown CSM-103, which flew on Apollo 8. The Earth-orbit mission was originally supposed to use LM-2 as its lunar module, but the crew found numerous flaws in it, many associated with it being the first flight-ready lunar module off Grumman's production line.