Separate Business?

Hello, in 2019, I purchased my first rental property.  I intend to purchase additional properties in the future and would like these to be under the umbrella of a separate rental property investing business.  In the months prior to purchasing my first, I incurred some expenses (e.g. professional development) unrelated to the property itself.

 

I see that TT allows me to enter income and expenses related to the property in the "rental properties" section.    Given what I've said above, should I also set up a separate business?  Would I then just enter the expenses unrelated to the first property in that section?  And how would I link the income and expenses related to the property in the "rental properties" section to the income and expenses for the business I create?