How to edit theme

So I just installed free version and it is nothing like being shown in screenshots. I am talking about those 3 sections on home page:

1. In center there is a picture of two kids with “Kids Collection” written over it
2. On right side there are two images “Shoe Collection” and “Watch Collection”

These sections and some other are missing in the theme. My question is do I need to customize the theme to make it look like this?
If yes then do I need to customize HTML or is there any editor or options available in back end which I can play with to make it like this?