I have a 27 inch iMac-mid 2010 and I need to know what I need to upgrade to macOS Ventura!

It's not possible to update to Ventura on that model. The last supported macOS version that model can run is macOS 10.13 High Sierra.

You would need a newer computer to be able to update to Ventura. One of the models shown in the support document you posted from.

That model can't be upgraded past High Sierra. Get one listed in the Related Article above.

(229677)

What you need is a new Mac.