AC DC circuit mixed. Voltage at a point
Ground (those flat symbols at the bottom) is the point on your circuit that you'd consider to be 0 volts. Everything else is relative to ground. That means that "voltage at a point" is really "voltage between this point and ground."
\$V_{cc}\$ is just a DC voltage source, so you can treat it the same as any other DC source.
Superposition is a good idea. To simplify the circuit a little,


For any DC components, a capacitor looks like an open circuit - you can just rip it out and ignore that it was there.
For any AC components, a DC voltage source like \$V_{cc}\$ (which has an AC voltage of \$0\$ V) looks like a connection to ground. Likewise, a DC current source has an AC current of \$0\$ A, so it looks like an open circuit.