Starting with Arduino; building proximity sensor

Hi Team,
Looking for guidance to build a Proximity Sensor with an audio output to an external speaker over 3.5mm jack.
Am a total newbie and am looking for pointers of what to google for.

Proximity of what, and over what distance?

To detect if there is a person within 10ft.

To discriminate a person from other objects is probably much harder than you imagine, but with some effort the AMG8833 thermal imaging sensor could be made to work.