redirect to a content page when a link is clicked

redirect to a content page when a link is clicked

ive just started PHP and MYSQL, and been trying to figure out how i can
redirect to a page and display the content.
i have this PHP code that lists all my topic rows from my database
while ($row = $result->fetch_array()) {
echo '<a href="#"><p class="list" st>' . $row['topic'] . '<br /></a>';
}
it will list all the topics inside the <a href> markup.
when link is clicked, i will be redirected to a page where the content is
displayed based on the topic link.
i just need the logic how to create that page. basically i have page.php
which i plan to put the logic. but i dont know how to start.