Multisite Implementation Problem

Hello.

I have been tasked to translate a website and replicate the site in a subdirectory. I accepted it not knowing that the page was created on WordPress. I have never done any web authoring on WP.

I face a few problems which I hope someone can help:

Limitation: I only have the FTP details and WP-Login details. No details bout the host and no access to cPanel.

Site Url: example.com
WP Url: example.com/kernel

My initial approach was to create another installation of WP in example.com/frkernel
But I was stopped short as I couldnt access the cPanel. Can I install WP via FTP?

My next approach was to try and activate multisite; But I was stopped short in the create network step with the following Error: Your WordPress address must match your Site address before creating a Network. How can I go around this without risking the original site?

I would sincerely appreciate if anyone can roughly give me a mindmap on how to proceed on WP. Many thanks in advance.

eg.
1: Install new WP on subdirectory / Activate Multisite
2: Clone Website
3: Import Clone Website and replace all links to reflect new url
4: Change the language used on theme/pages.