planning a relaunch of Sharepoint - guidance requested

Hi Amy_Sutryn - With any luck, the SharePoint sites that have been created are modern Team sites and live under /teams folder of your SharePoint Online and only have a limited number of users who can see them, rather than the whole organisation.
If you want to use SharePoint for your curated, authoritative content I would suggest setting up modern Communication sites that will sit under /sites , with a Communication site at the 'root' of your SharePoint online to act as the 'home' site, with your whole organisation given permission to view these site collections.

If you do this you can use the /teams  and /sites address locations to differentiate between your official, all organisation information and other, less official SharePoint site collections.
A good place to start to find out about setting things up can be found in the Microsoft Docs article https://docs.microsoft.com/en-us/sharepoint/intelligent-internet-overview.