Thanks. I figured it out, actually. I took the steps outlined above, only substituting single quotes for the double quotes in the echo, like this:
if (is_front_page() ) {
echo ‘<meta property=”og:title” content=”Sentence Spotlight” />
<meta property=”og:site_name” content=”Sentence Spotlight” />
<meta property=”og:url” content=”www.sentencespotlight.com” />
<meta property=”og:description” content=”I pick good sentences and think about why they work.” />
<meta property=”og:image” content=”https://www.theperfectpoach.com/wp-content/uploads/2015/03/Sentence-Spotlight-Logo.jpg” />’;
}
