Can I claim 3 Capital improvement forms ST-124 and where do I enter the amounts? One was for a whole house air purifier to my furnace, fencing, retractable awning?

You cannot claim home improvements as capital improvements for the home that you reside in.  If it is investment property that is being rented out, you can add the improvements to the cost of the property and depreciate them.

The improvements to your home that you reside in will be added to the basis of the home when you sell the home.