The theme looks beautiful because the developer wanted to Pocasset her in a favorable light — filled texts, pictures. Such a filling is called demo data. You don't have one. And this is the problem with many free WP-themes: in the picture is cool, but as put — emptiness of some sort.
But often the sample data can be downloaded along with the theme, even several variants of the sample data. And free themes, they also have. Just not always easy to find, sometimes it is necessary to first install neskolko plugins.
Check if your theme demo data. Look in admin — Appearance, there may be Starter Sites or Demo templates. Here in this article we describe several ways in which can these data be buried https://www.vepp.ru/blog/5best-free-wordpress-themes
About free and premium themes is also a good article there.