Hi there,
the main issues that Page Speed Insights throws up are:
1. Defer render blocking resources – must cache plugins provide options to defer JS script loading which will remove them from the critical requests and stop them from render blocking.
2. LCP time – the Largetst Contentful Paint Element is your first featured image. This is being lazyloaded so it loads after everything else. You may want to check with the plugin developer to see if Above the Fold Images can be excluded.
2.1 The lazy loader is also a cause for CLS ( which doesn’t currently effect the ranking ) as you can see on intial load its leaving a much taller space then the image requires. You may want to consider a different plugin.
So ultimately you may want to look for a cache plugin or try Autoptimize ( which includes a good lazy loaded ) and our Tips here:
https://docs.generatepress.com/article/configuring-autoptimize/