Landing page - upload ready html files to server, make mailing list opt-in work

Hi

I have created 1-page landing page with AI website builder.
It has mail subscription form - it doesn't work - needs integration with mailing software.
It is in English but has 5 more language buttons - they don't work, must add /de, /es... subpages and translate with AI like DeepL (it has total 3 full sentences).
I have web-server where it can be hosted.
Or maybe convert it to wordpress theme? Not sure what will be fastest/easiest.

So:
make 5 sub-pages for other languages and translate with AI
make the email sign-up form work - has to be separate list for each language - please suggest mailing software to use. It can be super simple.

I will send you link to this page if you are interested