Hey Su, Travelling in North Korea is a risky thing as every moment of the traveler or the tourist will be closely monitored ... Only way one can travel to North Korea is through a travel operator or through an agency ... Independent travel is impossible here ... Every moment of yours like the channel you watch to the place you visit will be monitored and you ought to be super careful here ... Would suggest you to drop the plan as there are 194 more countries in this world to visit ... Happy and safe Travelling Bro!!!
Clearly not safe. Firstly, the visa itself is very hard to get and even if you manage to get the visa, you will be constantly watched over. So, just drop the plan and instead visit South Korea which is a very beautiful and vibrant city to explore.