There are two different errors here. The ones with error type two are the ones already guessed at by @1.21Gigawatts
The error type 3 means you have no point where you supply your pcb with power (as far as kicad is concerned). Add a powerflag to tell kicad where the supply comes from.
More details see: ErrType(3): Pin connected to some others pins but no pin to drive it