I'm a developer who worked in a restaurant as chef (until I got the dev job abroad). I've discovered a method how restaurants could be more efficient. I spent 2 years developing the product (as a side project), which is far from finished, but good enough to be used, tested, and improved.

I'm looking for a way to make restaurants try it, and I have a couple of questions:

• be confident, and sell right away as complete product, or be honest, and ask them to help me test, and improve it for free?
• how much to go public? Should I start advertising, and get them come to me, or reach out directly? How important is it to have social media appearance, intro website etc.? (I have an intro website, but it's very basic)
• how "legally professional" should I be? I have a company in which I'm contracting, and of which will pay the costs of this app. Should I open a separate company, and do all the legal stuff like terms and conditions, and legal agreements, or just do it in a "handshake agreement" manner?
• what the beginning measures of success are, and when to know how to go forward? In the beginning I'm expecting the product to evolve a lot. I guess it's not worth it in the beginning to spend a lot on marketing. When to do it?