When presenting from a desk:
Use a USB-connected condenser microphone like this.

Compare the sound of various USB microphones by searching YouTube for:
“Best USB condenser microphones”

When presenting in a larger room or studio:
Use a wireless system like this. With a lavalier mic like this.

Compare wireless systems and lavalier/lapel mics by searching YouTube for:
“Best wireless lapel microphone” and
“Best lavalier microphone“

When presenting from a desk:
If nothing else, a built-in webcam on a laptop could work, but there are better options that will make for a better presentation –

– If you have an iPhone and a Mac computer, you can use the iPhone rear-facing cameras instead of a built-in laptop webcam; view the guide.

– Buy a better webcam like this one. Or a higher-end webcam if the budget allows like this one.

– For the best quality, consider a mirrorless camera like this one (coupled with a 24MM or smaller lens). You can connect it directly to your computer, and it interfaces as if it were a webcam.

When using any of these upgraded camera choices, an extremely helpful tool that greatly improves the quality of your presentation is a teleprompter. Prompters can be used not only to place your notes directly in front of the camera, but you can also use the prompter display to show the other participants in video calls and more. Looking into the camera lens is equivalent to looking someone in the eye when interacting in person and makes your presentation more impactful.

When presenting in a larger room or studio:
You’ll want to use a larger camera like a mirrorless camera with at least a 35MM lens or perhaps a dedicated video camera that is capable of zooming.