server error

[topic line moderated – do not yell here]

Hi everyone!
When I finish the install process of Duplicator I simply go to my home page and I find this error:
“Internal Server Error
The server encountered an internal error or misconfiguration and was unable to complete your request.
Please contact the server administrator at [email protected] to inform them of the time this error occurred, and the actions you performed just before this error.
More information about this error may be available in the server error log.“

I really don’t know how to proceed, I’ve been trying few things but ‘m not expert.
In the installation log I can find those two Warnings:

“MEDIA SETTINGS WARNING: The table ‘wp_options’ has at least one the following values [‘upload_url_path’,’upload_path’] set please validate settings. These settings can be changed in the wp-admin by going to Settings->Media area see ‘Uploading Files’

WEB SERVER CONFIGURATION FILE BASIC SETUP:
created basic .htaccess file. If using IIS web.config this process will need to be done manually.“

Thank you very much for attention and hopefully for your help
Andrea