If you are targeting restaurants (if not pick a good segment, small business is huge) then I would suggest going at off hours (very early or late), going in person, and talking to the owner face to face.

Most likely if its a small business restaurant the owner will be there. Even better is buy breakfast or dinner at the restaurant.

Then when you get a chance explain the problem you are trying to solve and a brief explanation on what you are doing, with the goal of getting feedback and their opinion. Only then if the owner is interested in hearing more should you follow up with an official pitch/presentation on what you can do.

It's a hard and slow process but no one said #startuplife is easy