Try below steps to boost your Page speed score in Google page insights
This process is handled well by the plugins that also optimize CSS delivery, which we mentioned in the previous point: WP Super Minify or Autoptimize. Use them to improve PageSpeed Insights score.
mages contribute, on average, for about 60% of a web page’s total size – this is the largest factor influencing loading times. The optimization process can considerably reduce the size of your images by removing unnecessary information, and by smartly re-compressing them using the most appropriate algorithms.
The optimization may be handled in different ways. Lossless optimization is moderate and it is recommended for technical drawings where no details should be removed from the image. Lossy optimization can radically improve the website speed by shrinking images more aggressively. However, this will not interfere with the visual aspect of your image. Images will still be properly displayed on the web, and the optimization will not disturb the way users see the images online.
Improve server response time
Slow response time may be caused by several issues: poor web hosting, web server setup, traffic overload or too many resources used. Google’s optimal server response time recommendation is set below 200ms.
Among other things, having too many poorly coded plugins may affect the server’s response times.
Avoid multiple landing page redirects
Redirects are a nice tool for getting people exactly where you want them on your website. However, unnecessary redirects will also cause delays and make it more difficult to improve PageSpeed Insights score for your WordPress site.
Google isn’t particularly fond of redirects in any shape or form. However, when you do need to use them, make sure that you have only one redirect for a single URL.
If you want just simple one-time 301 redirects, try out a plugin called Linker