When Poland joined the free market (EU) they went from a command economy to a free market economy.
No, It happened when Poland switched from Communism in 1989:
Joining EU from economic point of view meant unifying laws with those of EU and joining EU free trade zone, not EU free economy zone.
Then why is there restrictions of business and requirements for education and certificates to do even something as silly as real estate agency?
Because it's not completely free economy, as it nowhere is. Poland scored only 50th place in Economic Freedom ranking (although strictly speaking economic freedom is not only thing which it measures), so don't expect too much.
Any one care to explain for did the EU forget to send the memo to Poland.
What EU laws count in Poland? Anyone?
EU is not liberal economy zone. It doesn't forces completely liberal market, but also restricts it in the same time with it's regulations. So Poland is without few exceptions according to EU laws.