You can translate the content on the landing page, like the navigation, info boxes, and demo info if you log in as admin and then open the translation menu.
There select the “AVATAR” group. There you will see the strings, and you can translate them into your language
https:://yoursite.com/login
You can manage them if you log in as admin, and there access the “Landin page” menu.
If you want to modify the project with your own landing page here is how you can achieve that.
Disable the landing page from the settings page.
In that case, you will need to install the landing on the subdomain/domain and have the system on another location.
ex on the main domain you will have the landing page, which can be WordPress or any HTML website.
And on a subdomain, install the project
ex