Is it possible to change the them of just the home page? I want to either redesign the home page or use the home page from another template and tweak the colors, fonts etc. to match of course.
Is this possible with one of the free templates?
It is not possible without the help of a developer. The dev will upload the sections used within that template into your store and include theme inside of the index.json file and tidy up any conflicting code.