how to remove two images from theme

How can I remove two red buttons from both sides of the site? They are supposed to change images the on slider, however the left one covers social buttons (which, on the other hand, I also don't know how to remove - changing it in "Social Buttons" section doesn't help).

Hi!
Could you give us the URL of your website?

It's zacznijzyc.pl

I'd like also to remove the whole slider (too big) and place a logo and static image (about 50% of the slider width) in place of it. Is it possible?

To remove slider you can simply turn it off on page ThemeSettings --> Slider --> Show slider on home/inner pages. It is possible to insert an image,but we don't provide any services, paid or unpaid, for editing themes for individual users.