I can do step 2 (admin view) but when I try to do step 3 (site view) I get the error message "Invalid controller class: display".
For reasons I don't understand, the DisplayController class (in components/com_helloworld/src/Controller folder) doesn't seem to get loaded.
I checked the administrator/cache/autoload_ps4.php file and there are two lines in there as follows:
'JohnSmith\\Component\\HelloWorld\\Administrator\\' => [JPATH_ADMINISTRATOR . '/components/com_helloworld/src'],
'JohnSmith\\Component\\HelloWorld\\Site\\' => [JPATH_SITE . '/components/com_helloworld/src'],
So I think this is OK.
Any ideas about how to troubleshoot would be much appreciated. Thanks!