So, a little market research, door to door, online community pages, newspaper maybe, just to sample the interest. If you go out personally (go to te Walmart and canvas folk, lol), see if peoples' eyes light up when you mention it. Don't believe them if you get a half-hearted, bored expression cuz they don't want to hurt your feelings or might come in once a week to buy a pack of gum. Look for backers in town, if there is anyone with money. Some business people might benefit from the booming business you'll get, lol. You don't need to get a bank loan, but there may be some that would speculate with some start-up costs.
Be real, real careful opening a restuarant. They are tricky and lots of people with experience think they could master the art. But already you are indicating that you don't have a lot of experience with business, accounting, and marketing strategies, so you should really partner with someone who does. And don't think you can be a chef! You will be needed other places, especially to cover those sick calls all over on any given day. My husband was an executive chef and we used to talk about the reasons - for the most part - that a restuarant would take off or fail.
As for the market (one venture at a time kiddo), the store might require a bit of updating, renovating to moderity, but also keep the old-fashioned flavor, literally and figuratively. You might offer free wifi on a patio set up. Maybe even espresso machine, though that might actually alienate some potential customers, especially some of the older ones who don't like the new culture - even though they would love the sentimentality of having the store reopen.
If you have your own town council or county seat nearby, check out if they have community block grant funds available for what you want to do. There are other kinds of funds for business renovation and restoration, such as redevelopment projects in some places, if you can make a case. You might even find an historical society interested. The possibilities are there.