27" imac 2020 as 2nd monitor for MBP2017

Hi All,

So.. the Apple cables thing. I have a MacBookPro 2017 (only has USB-C ports) - it's a work machine and has VPN to work only data. I have to use it for certain things.

I'd like to use my new 27" iMac 2020 as the monitor for the MBP - I'm working in Tableau and really need the bigger monitor. This bad boy has a lot of different ports.

How do I do this? What cable do I need? USB-C on both ends? I did try that, with the charging cable I have for my iPad - but it didn't work. But that's a charging cable. So maybe it's different?

So lost in Mac cable-port-land.

Then once I have them linked, how do I share?

TIA

JD