I also got lost, didn't know how to open the store for sales. This is up my alley otherwise, nice little store, would play. Cool comic art too.
Viewing post in Just Start A Market jam comments
That it is, I managed to sell an apple. Turns out my problem is mostly technical - it took me a while to place a shelf, I clicked around until I found a spot where it finally happened. It's the same with other tools - I can remove the floor tiles (though I have to click a bit lower than the tile itself) but placing new ones, or walls or other things is very hard and random.