Socket.io: getting information from all other clients who are already in a room

Question

I am working with socket.io and I am trying to get some information from all of the other clients who are already in the room when a new client joins but I am a bit lost on what to do. On the client side, each socket client has some personal information like name, userId, and color associated with it, looking like this:

import { io, Socket } from 'socket.io-client';

class SocketClient {
  socket: Socket;
  userId: string;
  name: string;
  color: string;
  roomId: number;
}

Upon joining a room, I would like to know this information about all other clients, but I am a bit confused and I feel like the method I am working with so far is overly complicated for no reason. Here is what I'm doing

CLIENT SIDE: 
type UserId = string; 
type UserInfo = {color: string, name: string}
type UserSelectionMap_t = Map<UserId, UserInfo>;

public async joinRoom() {
   // join the room with this call 
    this.socket.emit(
        'workbook:subscribe',
        roomId: this.room,
    );
    // Now I want the information from the other clients in the room
    this.setUserMap(await this.getOtherUsers());
  }

async getSelections(): Promise<UserSelectionMap_t> {
    return new Promise((resolve, _reject) => {
      this.socket.emit(
         'listUsers',
         roomId: this.roomId,
         function (users: UserInformationMap_t) {
            resolve(users);
          },
       );
    });
  }

Now on the server side I think I need something like this which calls back to the client

// this function gets called on a 'listUsers' message:
function handleListUsers(roomId: number): UserSelectionMap_t {
  let idToInfoMap = new Map<UserId, UserInfo>();
  // - call into each client and get their userId and workbookId?
  // - Do I need another emit to client here 
  //   triggering a callback which would return the users information?
  return idToInfoMap;
}

Is this the best way to be doing this? It seems like a lot of client-server chit chat just to get some information. And if this is the best way, if each client emits their information, how do I organize the returns from multiple clients into a UserSelectionMap_t?