Please next time, follow the forum guidelines and create a new topic.
For the red line on mobile, that is a bit strange but it is meant to be a container for content. On desktop there is a checkbox that hides the whole box but on mobile, there is no same option and the block is displayed even if it is empty. Note you should have some text there and a button to lead customers to the pages you want.
For the mobile slider, you need to do a few things. First, you need to select a collection with more the 4 products. Then under Mobile layout enable “Enable swipe on mobile” and choose 1 or 2 column layout. Note: slider does not seems to work with dummy products, probably because number or dummy products.
Here is a screenshot: you can see two section, first with 1 column and second with 2 column mobile layout.
To make exactly the same as fuji sports there is some work or even choosing a different slider library.