Is there a way to track how many users have connected to my web?
general data like their IP, etc.

Not with Zenphoto itself except a simple hitcount. Use a specialized statistics tool like https://matomo.org/ for a privacy friendly way (we use the free self hosted version). Or if you care less something like Google Analytics.

I got and installed Matomo.....

Should I be using the javascript or log analytics?

I need to add javascript to every page? (PHP)? or just the main one?

OK... I found the plugin for Zenphoto...
Where does site ID come from? is that in Settings-Websites-manage?

Please see https://matomo.org/faq/general/faq_19212/

OK... it is as I assumed.

Still not seeing data.... I doubt my site has much traffic. However, I would assume that even a few visits would show up. Is there any way I can test?

Once Again.... never mind. working.