Get Username (users slug)

$Username = bp_core_get_username($UserId);

Get xProfile fields Name

$DisplayName = xprofile_get_field_data('Name', bp_loggedin_user_id() );

Does member exist?

  $user = get_user_by('email', $email);      //Returns WP_User object on success, false on failure
  if ($user !== False)
  {
    //----- THIS USER IS ALREADY A MEMBER -----
    $UserId = $user->ID;
    
  }