Edit Homepage Liquid Code, Where is the file? (Dawn)

[mralberget4a]

I want to customize some content on my homepage based on the user location, but can't find the liquid file, only index.json. 

Where can I find the file? Or is there another way to achieve this? Basically I want to keep all the elements but change all the images, collection, text etc. 

Edit: Would it be possible to customize by adding  a subdomain? 

[JackyYan]

I thought there was a liquid file for the homepage as well until I found my <h1> in the index.json. So it is where you customize content on the homepage. I assume.