Share on Facebook not working properly

When I try and share any post it doesn’t take any of the post info other than the link. It won’t bring over a picture or thumbnail and no matter which post it is it shows the website’s main title tag and description. What is wrong here? https://500hpc.com Thanks

Same if I copy a URL and try to share it on Facebook. With every other site I’ve ever encountered it’ll make a neat thumbnail of something on that page and take that pages title and content etc. But not with my site. I may have messed something up when trying to hide the title from displaying up top. Help please.