I started playing the game because I see there were achievements. I completed the tutorial, build a market and have 55 of population and I still have 0 achievements... They cannot be achieved in easy mode or is it a bug?

I'm not sure if it's just a random sell x resource quest, but I had a side objective to sell 70 stone in the trade interface. I was forced to clear the storage of my store(70 units) in order to be able to complete it as it refused to complete the objective until EXACTLY 70 stone was sold in one sell button click. Ideally a quest like that would have a tracker display(with variable stored to ensure exact requirement is met) to prevent having to buy a resource out just to turn around and sell it....

Am I supposed to do something with him? I don't understand why there is this weird hut with a geezer in it.

Not sure what happened there, did you maybe forget to add a USK rating for the German market?

Is there a French version planned in the future?