Is it all the pages of your site or just specific pages, @stanglaser? I looked at the site you are using as your Square Online Store and it loaded quickly for me.
It might’ve been My Internet connection
That can sometimes be the case! If you are seeing slowness on specific pages it helps to review what you've added to the page. Sometimes people add enough content that it can take a while to load, in which case you can resolve that by using multiple pages instead of a single page.
Square Community
Square Products