Odds are you have assigned a Static Front Page under Settings -> Reading. Whenever you assign a static page as your front-page, WordPress will display that page’s content instead of your blog posts. You can assign a separate page as your “Posts Page” which, when displayed, will display your blog posts. You can either assign a Posts Page or change the setting to display your latest posts. For more information you may read:
What is: Static Front Page by Syed Balkhi at WPBeginner