Human rights

How specific do I have to be for my legal goals in my PS? For a unicorn goal like international human rights, how do I articulate without sounding like a naive kid trying to save the world lol? Also, I am trying to gain experience (and also money lol) in litigation or international arbitration or something in a big law or prestigious firm before transitioning to the human rights domain and I am not sure if it’s the best idea to mention that as I feel like it detracts from my main goal and motivation of going to law school. Any advice from anyone would be greatly appreciated!