Hello sefirnecati. I saw your source code errors (file PID.err included in your upload) and also your code file. All those errors are because you are trying to use variables (maybe of type float) that are not declarated anywhere. I don't know too much about PID controllers but I will suggest you to avoid using floats because they are too expensive in processing resources like CPU cycles and RAM memory. Try to search at Microchip's website, they have a lot of information regarding this topic and many others too. Also CCS has help containing the built-in functions to control the CCP (PWM) peripheral.
Best regards, Yosmany325.
See at these application notes to have a better idea of how to do that
Application Note AN532: Servo Control of a DC Brush Motor
https://www.microchip.com/wwwAppNotes/AppNotes.aspx?appnote=en010998
AN893: Low-Cost Bidirectional Brushed DC Motor Control Using the PIC16F684
https://www.microchip.com/wwwAppNotes/AppNotes.aspx?appnote=en012134
More information related to motor control
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Information related to PID control
**broken link removed**
Hope this help you.