Philosophy has many different shades and colors (Philosophy of language, science, mathematics), and there is also a "branch" asking questions related to the meaning of life.

I can't tell you where you could/should start, because I feel like I would already influence you too much by taking some sort of choice away from you.

I will link a few essays I could find that are available for free and are not too long. I'm already influencing you a little bit by making this selection, but I urge you to do your own research: If you like one of the stories, try to find out who was influenced by whom (e.g. Kafka doesn't directly address meaning but influenced Camus; Nietzsche was influenced by Schopenhauer), and consider reading things challenging the author.

[1] The Last Question - Isaac Asimov (http://www.physics.princeton.edu/ph115/LQ.pdf)

[2] Metamorphosis - Franz Kafka (http://www.gutenberg.org/ebooks/5200)

[3] A Clean, Well-Lighted Place - Ernest Hemingway (http://www.url-der.org/a_clean_well_lighted_place.pdf)

[4] On Truth and Lies in an Extra-Moral Sense - Friedrich Nietzsche (http://www.jpcatholic.com/NCUpdf/Nietzsche.pdf)

I've often see people link the Stanford Encyclopedia of Philosophy, so I'm gonna do it as well: http://plato.stanford.edu/index.html

While I'm writing this gutenberg.org seems to have some problems, but just search for "Metamorphosis Kafka", and you should find plenty of other sources.