There was only one rail door, the one without the canopy. The rest were truck docks. Our local history museum is in an old wholesale grocery building, and it has a very similar arrangement, although ours is about three times larger - but still, just one rail door.
I tried to find the company name for you, without success. A good source is usually obituaries, where so-and-so worked for "Smith Wholesale Grocers". So I search for the fragments I can see, such as "Wholesale Grocers" and the town name. I came up with two business names, neither fitting the two or three visible letters.
One of the fun things about Waycross is the junction you have in the last picture. It's so rare these days to find a full crossing with all four quadrant connections intact. The line at the bottom (actually WNW) doesn't go far any more, but it used to be a main from there to Albany.