Hello, @Dennis,
There are two possible options the theme provides for the single product layout.
1. Default Pre-built Layout.
2. Single Product Builder.
You will find the options under XStore >> Theme Settings >> WooCommerce >> Single Product Builder >> edit content of page: https://postimg.cc/w3Mcjtny
OR
Turn this Custom product option OFF and you will be able to choose from the Pre Built layout: https://postimg.cc/4YDFzvkS https://postimg.cc/xq6xsVVH
You can read our theme documentation on this here: https://xstore.helpscoutdocs.com/article/68-single-product-page
You can edit the product description by clicking here – https://gyazo.com/371432debc257924c7e8cd013001ba35 using Elementor – https://gyazo.com/fa9717a69b2f8131129d193197f22d6c
Regards 8Themes Team.