Hi Toufiq,
Hmmm thank you for your initial answer.
There would appear to be two versions of this doc, perhaps you might like to check your site?
https://www.joomshaper.com/blog/step-by-step-tutorial-for-creating-a-multilingual-joomla-site (by Arafat Bin Sultan 16 May 2017)
https://www.joomshaper.com/blog/how-to-create-a-multilingual-joomla-site-using-helix-ultimate (by Zareen Tasnim 22 September 2020)
The "new" one (how-to-create) is still for Joomla v3. Which turns out, is completely different to Joomla v4.x which is what I am using and hence one major part of the confusion (I was not "brung up" on J3x).
In J4.x the Options to set the language are not in a button top-right. but in the SideBarMenu squashed up... Likewise, templates: If I have selected another template (shock horror, a non-Joomshaper one?!?) how do I use that? The how-to-create assumes Helix. even using a Joomshaper template, the how-to get the templates integrated (and yes, if you duplicate before you set the license will cause problems and there is still a very annoying webfonts issue - please provide a how-to for that and/or fix the template. It IS to do with GoogleFontsAPIKey.
Unfortunately, the drive based movie link is still "whirring away" and after two hours I suspect I will not see the .mov contents...
Also, to follow the whole process, you have to be a SuperUser - doesn't say this anywhere :(
My issue is that how this "connects" to the Main Menu and subsequent activities. With Helix/SP Page Builder i want to see the Language Switcher, Main Menu and then any 'page' and/or 'article' is accosociated to a relevant language.
THEN, if I create a page (with SPPB) I need to create an identical one for each language. This is NOT an option I see to "duplicate" page, or even assign a language to it. It is not clear that you can only change the "default" on a duplicated Template Style (who that that was obvious?!?).
It would also help if someone just said/wrote/explained that you do not use "MainMenu". You have to "create another main menu" per language.
But finally, how do you set the default layout for SPPB Pro?
Why does this all have to be sooooo complicated? I know I am stupid but really?
I apologise for my frustration. I should be so much further ahead than I am right now.