I've recently picked up reading and want to start learning about philosophy but more particularly existentialism. My first exposure to existentialism and philosophy as a whole was through reading Dostoevsky's novels where I've read been working through his books starting with Notes from Underground all of which I've really liked.
I have also done some reading online into the field of existentialism but have only so far picked up Plato's The Republic as people recommended to read it first to get a better introduction to philosophy as a whole. While I can manage reading it, I find it very time consuming and am not particularly interested in his ideas as I am with existentialists such as Kierkegaard, Camus, Heidegger and Nietzsche so I'm wondering if its really essential for me to read the Republic first.
So my question really is should I read other books first, or can I just jump into something like Fear and Trembling. Also any recommendations into which specific books I should read to get a basic understanding of the different perspectives would be greatly appreciated.