What can we do to get just one single grocery store accepting monero?

Given grocery stores tend to use the currency corresponding to their government's authorized legal tender for use in payment of debts: a lot of small things. A select number of stores in different regions accept bitcoin one way or another, word-of-mouth to support purchasing with Monero through similar systems can encourage practical consideration of it. It will take the slow expansion of Bitcoin-accepting businesses to also accept Monero as value that can benefit the business. In general, I don't know of any specific grocery store in my region that accepts crypto, Monero has an uphill battle to see grocery deployment.