I am trying to find the storage amount that the Marketing Cloud Connect requires in SFDC. I know it creates 20 objects and I need to know how much space that will require.
Most of the objects that you mention largely relate to Connector configuration and you don't really need to be concerned with this impacting your data limit.
However, the majority of data storage by Marketing Cloud is related to email tracking data, which you can estimate using the Tracking Data Storage Calculator.
This storage amount can be significant, so you should consider also using the Tracking Data Cleanup feature to delete old email tracking data.