How do I change the home page to the registered user’s profile page

Check that your are on the home page, and that the user is logged in, and redirect if both are true:

function redir_user_wpse_187622() {
  if (is_home() && is_user_logged_in()) {
    $user_id = get_current_user_id();
    wp_safe_redirect(get_author_posts_url( $user_id));
  }
}
add_action('template_redirect','redir_user_wpse_187622');