Add space below a personal slider on homepage

Hi. First, thank you for the creation of this interesting theme and its sharing.
My main question:
I created my own slider instead of the initial posts slider, in the homepage, because I just wanted new images, not linked to the blog posts. I found a plugin for that and add a line of code at the beginning of index.php. It works nicely.
But the problem now is that this slider is touching the thumbnails below… (see the link).
How can I obtain some space ?
(I also think that features posts got too small high image but it is another subject).
Is there any code to add in the index.php or elsewhere in order to “unstick” this two elements ? Thank you very much if you can answer!
Have a nice geek day.
https://paulmolac.bzh/wordpresslocal