How does Elementor page relate to other site content?

[improvedexecutivefcns]

I have a website with multiple pages of content and an ecommerce section, all selectable by menu items on the main page. I want to install a landing page that will be in front of the main page and all the menu items. The LP will contain some graphics and brief summaries of more expansive content on the site, along with a marketing pitch and a sign-in to access the main page and menu items.

I'm concerned that if I set up and publish a landing page that it will replace all the other content on the main page. Is that how a LP will work? If so, where on my site do I install it?