Primary residence converted to a rental property

Our home of 20 years was converted to a rental property in August 2022.  How do I add previous capital improvements dating back to 2004-2008, etc. to the basis?  I can combine expenses into bathroom remodel, kitchen remodel, flooring, etc.  Do I backdate?  I assume the amortization would begin the date the rental was placed into service vs. the date the work was done. Is this correct?  Thanks!