Hello pasicr
The electrical characteristics of the LEDs in the ISIS Proteus simulator are:
2.2 Volts when they are crossed by 10mAmp.
2.2 Volts is the parameter called VF. (Forward Voltage).
10mAmp. is the parameter called IF. (Forward Current).
The formula to find the value of current limiting resistor for the segments of the display that you mention would be: (Vcc - (Vf1 + Vf2)) / If = Rx.
You say in your original message that you are polarizing, these Display's, with 12VDC. But you need to know the IF parameter and the VF parameter to find the value of Rx.
Let's assume that your Display LED’s have the same characteristics as the ISIS Proteus simulator, then:
(12 - (2.2 + 2.2)) / 0.010 = 760 Ohms = Rx.
Now, your second question:
how to connect each common cathode and anode to PIC MCU to avoid burning port, and to reach max brightness LEDs,
First, you have to analyze the data sheets of the PIC you're using to find out if the PIC can handle the stream of your Displays.
Second, how will you handle displays in a multiplexed system or how. ??
I think that your display would be more understandable drawn as seen in the attached image.