<head>
    <title>Title</title>
  </head>
  <body>
  <p><b>2023.02.20</b></p>
  <p>This is the first paragraph.</p>
  <p>This is the second.</p>
  </body>

Save that as "blogpost.htm" somewhere a web server can see it.

Add stylesheets and so on as you get more comfortable, but it really is that simple. All that matters in the long run is what you put between the <p> tags.