Q: Folder with a question mark on a white screen.

I was editing photos on my computer and a window popped up that said "critically low on space" and then my computer screen went white and restarted and then a folder with a question mark popped up and now it won’t go away. I did the command + option + R while holding the power button to reboot the internet or whatever and then I wen to "reinstall OS X" and then I got to a screen that asked me to select the disk where I wanted to install OS X, but no disk came up for me to click. Now I am panicking and need some major help. My computer was doing weird things about 5 months ago where the screen was going white and a bunch of different languages (like the matrix) were running across my screen and I took it to the apple store and paid 300 bucks for them to fix my computer.