What are the strategies to improve the first time user experience & lighthouse audit score?

I tried the lighthouse audit from chrome browser. The results are below.

Is there any way to improve the initial load experience for the users ?

May be a loader / splash screen before all the Javascripts are loaded and progressively enhanced ? Right now we have to see a plain white screen before the rendered html appears.

This is critical for the mobile phone users with slow internet especially the first time visitors to the site who would leave otherwise.

There are 5-6 topics covering this exact thing. Try a search.