How to read this basic schematic?
That is a really crappy circuit since it depends on the gain of the transistor being just right.  Real transistor gains vary widely, even within the same production lot.  Competently designed circuits work from the minimum guaranteed gain of the transistor to at least 10 time that, preferably to infinite gain.

I would start with the transistor stage setting its own DC bias so that the output voltage is near the middle of its range.  The signal from the LDR would be AC coupled into that stage.  The LDR would have a pulldown at least so that it and the pulldown produce a voltage signal by themselves.  This would be the signal fed into the amplifier stage thru a coupling capacitor.

For extra credit, come up with a auto-biasing scheme that keeps the output near the middle of its range regardless of average ambient light level.