Dear Stefano
Thank you for reaching out to the Microsoft Community. We are happy to assist you.
Regarding your question, if you can't find the Site Information > Delete site feature you might want to re-check if your site is Root Site.
Because you mentioned you are your company Admin, you can check for Root Site on SharePoint Admin Center > Active Sites > sort by alphabet, the first site is the Root Site although we don't recommend deleting Root Site since Root Site is the top-level site of your SharePoint tenant and cannot be deleted.
For more details about Root site please refer to
Modernize your root site - SharePoint in Microsoft 365 | Microsoft Learn
For more details about deleting Site please refer to
Delete a site - SharePoint in Microsoft 365 | Microsoft Learn
You can consider making a new site and refrain from using Root Site in the future because it tends to cause a lot of problems.
If you have any other questions or need further assistance, feel free to ask, also if you found the information useful, feel free to mark it as the answer - it can really help others in the community who are facing similar questions.
Best regards,
Jess - MSFT | Microsoft Community Moderator