Hi there,
I see that you’re using CDN and that could help.
If you’re not using one, consider using a caching/optimization plugin.
You then start playing around with the optimization plugin configuration.
I’ve checked the site and perhaps it could take advantage of JS or CSS combine/aggregate.
While aggregate/combine is known to cause issues, if it’s configured properly, sites will have significant performance improvement. 🙂
This article is quite helpful. https://kinsta.com/blog/eliminate-render-blocking-javascript-css/
It’s the same principle behind Tom’s recommendation. https://generatepress.com/forums/topic/eliminate-render-blocking-resources-2/#post-1527484
As for Reduce initial server response time:
This is pretty tricky as the quality of the server may play a part on this.