Hi there,
Pagespeed Insights can be helpful: https://developers.google.com/speed/pagespeed/insights/
They show you exactly which images could still be optimized. How are you optimizing them at the moment?
As for the javascript, the biggest issues there are your Google ads. There’s also sitespeed-js – not sure what that is?
If you use a plugin like Smush (or another, there are tons), it can optimize your images and implement lazy loading to fix the defer offscreen images.