I'm opening a shop and I'm willing to sell anything legal. I don't care what you want to buy, I care about being able to provide you with exemplary customer service and quality products.
With that being said, what do you want to buy??
You can sell whatever is required for people. If you store has enough space, starting from a pin to electrical goods can be sold. People always prefer to spend less time and get all things from one place. Your business will cover the market. All the best.