Push a stream of air from your throat through your open mouth. No tongue or lip contact.

Americans pronounce who's as hooz (/huz/). You'll hear it in sentences like "Who's in charge of the marketing department?".
Record yourself saying "who's" and play it back. The mic stays on your device — nothing's uploaded.
1 syllable, 3 sounds. Explore each sound's mouth shape and how it's made.