Image position fixed and center

Hello,
I’m trying to use the Owl Carousel above a full screen background slideshow.
I would like my pictures (products) carousel to appear always in the same position on the background no matter screen sizes my customers will have, centered too.
I tried many things but I don’t know if my widget area where I use the Owl should be position fixed also. And then should I upload only pictures with the same sizes?
Sorry it’s kinda hard to explain hope you’ll be able to help me, here is my website https://s556743003.onlinehome.us/

https://www.ads-software.com/plugins/owl-carousel/