Hi German,
I hope you are well today and thank you for your questions.
I wanted to mention that there was an existing website and I just changed the theme to yours so it seems things got mixed up.
Yes, this happens when you import the demo content on the existing site.
How can I make sure the site looks exactly like the demo so I can start adjusting by organizing and placing the text and images from the previous site into your theme?
If you have any development site then I recommend you to first import the demo content on it to check whether everything is fine.
In your existing site does the demo content created some pages after importing the demo content?
If yes then please visit those pages to know which one you would like to set as your site home page.
Best regards,
Shufflehound team