Problem after installing theme - Product Description

Hi there. Im having a problem with my store. After importing a theme, i see that i cant add sections/blocks to my product page. So i cant achieve the look that the demo theme had. Ill attach some pictures of the demo theme.
I need to change something in the .liquid files of the product page?
How can i set up the code to allow me add sections and blocks at the description of the products?

Hi, @Blumaroo .

Thank you for reaching out and bringing this to our attention.

I understand that you’ve imported a theme and you’re unable to add sections to the product page. Just to confirm, are you using a Shopify-supported theme? Or, are you using a third-party or custom theme?

If you’re using a Shopify-supported theme, then we’d recommend checking to see if you have the latest version of the theme as only Online store 2.0 versions will be able to add sections to the product page. On that note, if you encounter any issues with this, then it looks like we’ll need to access your account in order to resolve this issue. While we’re unable to provide account-specific support via the Shopify Community, we’d be happy to continue assisting you through live chat, email, or callback. Simply visit the Shopify Help Center and log into your account to create a support request.

If you’re using a third-party or custom theme, then we’d recommend checking with the theme developers on where to get support for your theme. If the developers don’t offer customization support, then you may want to consider hiring a developer to assist you with your theme. On that note, if you need help finding a developer for your store, then we’d recommend checking out our directory of certified developers on Shopify Experts.

That being said, did you get a chance to try some of our free themes? If so, then does the same issue persist with one of our themes?