Startup problem

Hi
I start with Nextcloud and it’s not so simple!
I did not find a clear tutorial!
I am at OVH with my site rousselle.fr
I created a folder /cloud.
I copied in this folder the extracted files from the archive nextcloud-16.0.1.zip
And I generated the ssl certificate for cloud.rousselle.fr
I tested http and https access with a small php file.
When I launch https://cloud.rousselle.fr, I get a nice Nextcloud blue window with the message in French…
"
Internal Server Error

The server is unable to execute your request.
If this happens again, please send the technical details below to the server administrator.
The server log file can provide more information.
Technical information

    Remote address: 14.236 ...
    ID of the application: XOiOS ...
    "
    Did I miss something?
    Does calling my zone "cloud" and not "nextcloud" can affect operations?
    Hoping for help from some specialists of this software! Thank you in advance
    Jean-Jacques

my french is quite rusty but i think this howto (even in french) would perhaps help you

as for your issue: you haven’t posted enough information about your envorinment/server/setup so that it’s almost impossible to give you any valid answer

awww… crossposting of this one here…

For Internal Server Errors you must check your webserver logfiles because it is a generic error and can be related to many many different issues:
https://docs.nextcloud.com/server/16/admin_manual/issues/general_troubleshooting.html#logfiles