I finally managed to install the site,
I switched to php 7.4 NATIVE, it didn't work right away, white page on the admin and on the home page, but I did a manipulation in htaccess (mbstring), and after it worked, I deleted the piece of code that I had added in htaccess and it still works, luckily, I can't explain why...?
However I have a lot of errors on the login test page:

#[Web Server]  Apache http server version 2.4.7 or later (you have LiteSpeed)

#[Optional requirements] deflate module enabled in Apache
Needed for compressing files, for a faster page-load

#[other server programs]
*Antivirus is not enabled. Please go to Other server programs in Site Settings to change this.
*Antiword is not correctly set up.
*Ghostscript is not correctly set up.
*JPEG Image Optimizers
jpegtran is not correctly set up.
jpegoptim is not correctly set up.
*Backup/restore
mysql is not correctly set up.
mysqldump is not correctly set up.
*PDF-To-Text
pdftotext is not correctly set up.
*PNG Image Optimizers
optipng is not correctly set up.
advpng is not correctly set up.

#[Site configuration]
*There is a problem with the public link for service.png and 2 other images. Please check your public/images directory for possible permission problems. Manage images
*Automated backup monitoring is not set up. Please go to Backups and document storage in Site Settings to change this. Manage automated backups
*Your site is in development mode, but if you're developing modules you would not be able to see PHP errors and notices. (The ERROR_REPORTING_LEVEL should be set to (E_ALL | E_NOTICE | E_STRICT) in your zenario_siteconfig.php file - or click the hammer icon at the bottom left of Organizer to fully enable the site).
*This site contains user-related data, but you are not protecting your admin-login with two-factor authentication. Please edit the zenario_custom/site_description.yaml file to enable two-factor authentication.
*There is an unknown file in the Zenario root directory: error_log. Please remove this if possible.
*The .htaccess file exists and is readable, but Friendly URLs are disabled. Please go to URL format, aliases and XML sitemap in Site Settings to change this.
*The default timezone is not set in site settings. Please go to Date and Time in Site Settings to change this.

#[Content items in draft form]

*html_5/privacy-policy,en-us is in draft mode.
This page is a special page and it should be published.
Created 52 mins ago (5 Aug 2020 20:06) by System Administrator (ABC_Admin).
*html_2/second-page,en-us is in draft mode.
Created 52 mins ago (5 Aug 2020 20:06) by System Administrator (ABC_Admin).

I started testing quickly and I get an error loading a logo image, I manage to load and place the image after several error messages.
I have to try to fix the security message about the htaccess file.
I will test more in depth tomorrow to see what problems I will surely encounter.

Do you think this configuration is viable or does it pose security problems?

Thanks.