How can I replace the three selectors? This is what I'm doing

[joyce.evelyn15]

{ selector h1, h2, p, text-align: center; }

[hbar1st]

the word selector is not a ‘selector’
so you should delete that
the words h1,h2,p are the selectors.

The syntax for writing a selector is like below:

name-of-selectors {
property: value;
}

So you have to place the h1,h2,p in the name-of-selectors area
and the text-align: center; in the property: value; area

[Nathan.clark88]

You can replace the three selectors in your code with a class or a group of classes, like this:

.center-align {
  text-align: center;
}

And then you can apply this class to the relevant elements, like this:

<h1 class="center-align">...</h1>
<h2 class="center-align">...</h2>
<p class="center-align">...</p>

Or, if you want to group multiple classes, you can use the class syntax as follows:

.header, .paragraph {
  text-align: center;
}

And then you can apply these classes to the relevant elements:

<h1 class="header">...</h1>
<h2 class="header">...</h2>
<p class="paragraph">...</p>

[joyce.evelyn15]

Now it makes sense, now looks so easy!!!
It’s working, thank you so much.