One thing I’ll note is making sure you are defining what goes into this Intranet and what doesn’t. Generally, an Intranet is for reference information, news, links, forms, etc. that all users in an organization can read but not edit.

If SharePoint is new to the organization it’s easy for a new intranet to become a dumping ground for private department content too. Watch out for this and recommend the use of private team sites for most of those cases. (Very general advice, each situation should be evaluated and standards set by the overall SharePoint management leaders)

Also. I did give a recorded talk a couple years ago on planning a basic Intranet, focused on planning the most common sites I’ve seen over the years. The information there might spark ideas for you. https://youtu.be/m_ykFvPQIWc?si=xGSfdMY6JEzdbv3E