all the devices are connected with positive terminals in series, positive of the battery to positive of the ammeter, -ve of the ammeter to say +ve of diode, -ve of diode to any terminal of resistor/bulb since they dont have any polarity and can be connected in any way, then back again to the -ve of the battery. To connect voltmeter in parallel with the bulb, +ve of the voltmeter to be connected with the terminal of the bulb(which u can say acts as the +ve terminal since all connections are made with +ve first) and a connection from the -ve of the voltmeter is made to the other end of the bulb.
note it: voltmeter is always connected in parallel because of its high resistance.
