Example of save another data to a user with Firebase

user.ts

import { AngularFireDatabase } from 'angularfire2/database';
import { Injectable } from '@angular/core';
import { AngularFireAuth } from 'angularfire2/auth';
import * as firebase from 'firebase/app';

@Injectable()
export class AccountProvider {
  private PATH = 'usuarios/';

  constructor(public auth: AngularFireAuth, private db: AngularFireDatabase) { }

  public createAccount(user: any) {
    return new Promise((resolve, reject) => {
      this.auth.auth.createUserWithEmailAndPassword(user.email, user.password)
        .then((firebaseUser: firebase.User) => {
          this.db.object(this.PATH + firebaseUser.uid).set({ cpf: 'aqui vai o cpf', rg: '' });

          // Aqui eu salvo o nome pois posso acessar mais facilmente com o AngularFireAuth
          firebaseUser.updateProfile({ displayName: user.name, photoURL: null });

          resolve();
        })
        .catch(e => {
          reject(e);
        });
    });
  }

  getUserName() {
    return this.auth.auth.currentUser.displayName;
  }

  getOtherUserValues() {
    return this.db.object(this.PATH + this.auth.auth.currentUser.uid)
      .snapshotChanges()
      .map(changes => {
        return { key: changes.key, ...changes.payload.val() };
      });
  }
}