Combining features from two different themes

I’ve got an existing blog that I want to update the look of the homepage. I’ve found a theme that has the features I want and I’ve made some customizations to the layout but because I want to keep the subpage layout I have on my current blog I’m looking for a way to show the home.php file of the new design on my current site.

I’ve been looking into child themes and get_template_part options but I haven’t been to able to either use these in the correct fashion or find the specific solution to the problem.

I did try taking out the code of the new layout blog for the features but it is combined with the stylesheet, functions.php, and header functions and I wasn’t able to put all of the correct pieces together to not get an error.

If you have any ideas that might lead me in the right direction they would be much appreciated. Thanks