wearable arduino motion sensors. PLEASE HELP

First arduino project
want to create a divice that vibrates when someone is standing still for a certain amount of time ( will be used in public spaces). how do i make the device wireless? i need it to be very small as well
i know i need a vibrating motor, PIR sensor, Jumper wires and aruino uno- but how do i make this so it doesnt need to be plugged into the computer
really need the help
thank you

An Uno and breadboards are fine for software development, but for a small device you better use a smaller board, ready made (Mini...) or custom PCB. Also needed is a power supply (battery...), and soldering skills for the connections.

How''s the PIR and wireless part fit in? You're trying to detect a lack of someone standing in a certain area and send that to a PC? How far from the PIR/uC/wireless TX to where the Rx is? Which part vibrates? The Tx end or the Rx end?