WordPress Get User information after login or Signup

Solution:

You can try this

 function get_user_information() {
        if ( is_user_logged_in() ) {
            $current_user = wp_get_current_user();

           echo ( 'Welcome, registered user!'. esc_html( $current_user->user_email ) );

        } else {
            echo( 'Welcome, visitor!' );
        }
    }
    add_action( 'loop_start', 'get_user_information' );