There are so many things wrong with your post I don't know where to start and which one of them is the worst of them.
Cuba was a dictatorship, and no, in no country, even in a total authoritarian regime or in how you describe it communist rule you're not allocated your job and you can still decide what job you want to pursue. But, you're mixing the planning of the economy with the rules on this one.
Because North Korea is a socialist country, a planned economy run by the state, it doesn't matter who the lear is and what type of government is in the country. For example, Qatar is a monarchy where the king has absolute power, pretty close to a true dictatorship but that doesn't make it even remotely socialist or capitalist as those are being defined mostly on the economy runs. And everything in NK runs by the socialist manual.
Well, sorry to burst your bubble but you should listen to the people running those countries before you assume they are socialist:
https://www.thelocal.dk/20151101/danish-pm-in-us-denmark-is-not-socialist/
Of course comrade, of course, it's all fake propaganda. Now, how about you go to Venezuela and breathe o full load of rich and healthy socialist air?
Oh, and I'm talking about air since that's what they can afford currently.