How can I completely disable internal Mic and Webcam

I want to disable the internal Microphone on my laptop and the internal Webcam completely that they're no longer selectable, and no longer available?

I will only use my external Webcam, and my external (USB) headset.

The internal audio should still be available for playback.

Blacklist drivers

In both cases kernel drivers may be loaded for both, the internal sound card, and the webcam to be recognized by Ubuntu. We can find out which drivers are loaded by the following command in a terminal:

lsmod

From this list we can see which of these kernel modules may be responsible for our (specific) hardware (e.g. an Intel sound card may need the snd_hda_intel module).

Blacklisting these kernel module will stop this device from being recognized by your system. To do so we edit the file /etc/modprobe.d/blacklist.conf as root to add the following line:

blacklist <name_of_module>

See also: How can I control which sound card Ubuntu uses for playback?

In case we still need the internal audio card for playback audio we can just mute the input microphone source, e.g by running alsamixer in a terminal.

Blacklist the webcam driver and mute the Internal Mic from Alsamixer.

According to the informations you gave here, open a terminal and execute this command

Disable WebCam

echo 'blacklist webcamstudio' | sudo tee -a /etc/modprobe.d/blacklist.conf

Mute the microphone

To mute the internal microphone use the alsamixer.

Open a terminal and give this command

alsamixer

Navigate with arrow keys <--> and find the internal or mic channel and then press the M key on your keyboard to disable - mute [MM] the microphone. Esc to exit