I tested uploading two articles to see how the site looks with pictures, but for some reason it doesn't show on the homepage or the category article list. It does appear when you open the article though. I tried uploading the image to the blog options and the regular joomla options.
https://ibb.co/kKZWXps
https://ibb.co/kHW48jk
https://ibb.co/C0jSZ0m
https://ibb.co/Qj7Vj8f
https://ibb.co/4d63dX0
I left the login credentials in the hidden section just in case.