How to make a multilingual site on WP?

Question

Internationalization and localization

There is a site on the WP domain in the *.RU zone. It is
necessary to make a multilingual site on the *.COM domain.
The goal is to increase site visitors through search results.
I plan to use the polylang plugin
Please tell the beginner the correct sequential order of actions.
Is it better to use both domains for optimal search results or not?
Or maybe first transfer the site to a new *.com domain and already do multilingualism on it?