Is it more correct to promote a site or a landing page to it?

Question

Search Engine Optimization

Goodnight! I am familiar with SEO only in theory, now there is an opportunity to try myself in practice. What is the question, which, due to lack of experience, I cannot master on my own:
There is a website for the organization - a restaurant business. They work on a franchise, because specifically their site exists just to be, i.e. it contains contacts, the location of objects, and there is a duplication of some shares of the restaurant chain + sometimes their own. There was never any goal to move it, the network’s website with menus, online orders and other things is moved by the network itself, but all their promotion is aimed at Moscow and large cities, because. the bulk of the objects there.
Actually, we decided to try to move our site separately from the network, or rather the delivery service, in small towns where we have our own facilities. But since we only have promotions and links to the network’s website for ordering, then the client simply has nothing to do there - he will immediately leave the page. I figured that a landing page is required, which will say "order delivery" with its design :) and the "ORDER" button will switch to an online order already from the network's website. Actually, the goal is to promote this particular landing page in the search, because. on the site itself there is no menu, no prices - nothing that can be purposefully moved and presented to the client.
Am I thinking right? Does such a move make sense?

Answer 1

For SEO - site
For contextual advertising - Landing Page

Answer 2

Specially, so that there are no unnecessary thoughts, to do or not to do. Options, etc.)) We came up with a ready-made business. Franchising, you must have heard. There are answers to all questions)) This is when you take a ready-made turnkey business, I had a stall for many years, until 2014, before the crisis, then it was necessary to do something bigger. Then, with the last money, I bought a coffee-franchise.ru franchise for myself , why not, there is no torment and unnecessary thoughts, there is only one snag, you need to WORK If you have a ready-made system, this is only 50% of success))