Let me tell you if its really all that you want ? you can do it ! Move to website migrant.info.pl and you will find every piece of information regarding registration of business in Poland.
You are right. It is not difficult to set up a business in Poland.
In fact, setting up the business is probably the easiest part and as you have mentioned correctly, anyone can do it.
But when people say "it is very difficult", they don't necessarily mean the actual set up / registration of the business. They mean making the new business a success. I have not been a member of this forum for too long but in this short period of time I have read many posts from "dreamers" about opening kebab shops, bars, restaurants, hostels, kiosks, etc. etc. etc. and they believe that it will be sucessful.
I have said this a few times now. Poland, when you come here on holiday and Poland when you actually have to earn a living are two different things Now I have to read this :
I am planning to start a small take-out/kiosk in Warsaw. I will be visiting there in a few weeks to conduct further research. I am curious, how difficult is it to find a small location(6x4m2) to practice such a business?
Where does the "plan" to open a small kiosk in Warsaw come from, if the location is not yet even known? I would have assumed that the idea of opening a kiosk would be born by knowing the location and the feeling that a kiosk is exactly what is missing at that location. Not the other way around.
So yes, if you want to set up a business, go ahead, it is easy, anyone can do it. But that still does not mean that you will earn one single grosz from it.