Why can't I see/sell things on the farmers board

Let's start with some terminology:

• The Farm Orders Board is the board by your barn where you can sell items for experience and gold. There are a max of 9 different things that can be on the Farm Orders Board at a time.
• The Farm Market is the place where you can sell up to 4 things at once to other Country Escape players, and you can also buy stuff from other players here. The global list cycles every 5 minutes.

I think you're talking about the Market. The "globe" tab on the Market picks a set of people randomly that you can trade with every 5 minutes. Sometimes you'll see a ton of the same thing, and sometimes you won't see anything you want or can buy. There's no rhyme or reason to it, you've just got to roll with it.

If you want to buy and sell things with your friends, you have to do this through the "friends" tab on the Market. I've had the best luck trading with the people in my Co-Op, but I do believe people not in your Co-Op but who are Facebook friends will also show up on this list, assuming you're connected to Facebook.