Give the paragraph a border that is 4px wide, solid and red

so your paragraph has the class main-pg which should be written like this:

<p class="main-pg">My amazing website</p>

The class has to be written inside of the quotation marks only and doesn't need to be specified outside of those parameters.

then in the CSS you'll need a class selector which is a period --> . <--- and that code should look like this:

.main-pg {
   border: 4px solid red;
}

you are selecting the class that was defined in the html by using the period. Then inside of the curly brackets, you add the styling you want to apply.

and again its WHAT you want to do then a colon, then the styles and then stopping it with a semi-colon.

border: 4px solid red;

The syntax is wrong. Just give a class to the p element in your HTML file, like this, <p class="main-pg"></p>. Inside the CSS you can use the special id name with '.', like this,

.main-pg{ <- This is the p element special class name
  border: 4px solid red; <- You should use colon instead of equal sign and you forget use a semicolon after the property.
}

Look back at the previous video if you're not sure about something. Hope this help!