Landing Page based on the first page of the old site or on the new page?

Question

Design

I want a Landing Page, I have an active site, there are links to it on other sites, including those not on the first page.
What is the best thing to do in order not to lose the audience:
1. Create a Landing Page based on the first page, leaving, for example, the site menu of the old site at the top
2. or create it on a new, not the first page?
3. or even separately under a different name?
The site advertises a furniture salon - descriptions of models, photos, etc.