Checked your page and noticed that you use the wrong Bootstrap 4 page structure. I don’t have much time to help you, but I show you 2 examples with the carousel and the way it needs to be implemented.
Full width carousel
Small carousel similar to your idea scroll down to see
Please right click on the web pages and look in to the source of the pages to see how it’s done.
Bootstrap structure is:
Container > Row > Col (for example col-md-12) then your item.
I do advice you to first study Bootstrap 4 HTML structure to understand how it is done, you can’t not just drop components on a page. Pinegrow can spit out several Bootstrap 4 pages to study or use for your design and of course the Bootstrap 4 website is a good source of info.
Bootstrap 4 info