Squarespace code slowing page speed

Site URL: https://www.seeturtles.org/

I manage a few squarespace sites but am not a developer/coder. I'm working on improving the sites' SEO and page speed, using the Google Search Console. Under the tool's "PageSpeed Insights", I've optimized large photos to reduce loading time but the biggest remaining impediment appears to be third party code on the website from Squarespace (see screenshot). 

Is there extraneous code from Squarespace that I can remove without being an expert and not wreck my page? I've already removed Facebook pixel code as well as some Twitter code I had that I don't need.

If that would be the only problem. In total the squarespace page loads very slow. Is there anything I can improve regarding to the pagespeed?

The attached files are first the desktop version and second the mobile version. I am not a developer/code but I want to have a website which is competitive to others.