The First Contentful Paint (FCP) metric measures the time from when the page starts loading to when any part of the page's content is rendered on the screen.
First Contentful Paint (FCP) is an important, user-centric metric for measuring perceived load speed because it marks the first point in the page load timeline where the user can see anything on the screen—a fast FCP helps reassure the user that something is happening.
You just need to install and activate a cache plugin e.g, W3 Total Cache, which will help in removing the website cache which will ultimately increase the content delivery speed.