Every network card has a mac address, a serial number of sorts, assigned to it by which a network can identify you. It is a widely used way to restrict or monitor your access on a network and it could be useful in such cases to have a randomly assigned mac address to improve your privacy and anonymity. The script is just a bunch a of commands, you can run them separately if you want to, this just makes it easier to reuse instead of remembering every step. The mac address should change with every reconnect.

#!/bin/bash
read -p "This script changes your WiFi mac address. Use this at your
own risk and obey all local laws. By pressing enter you agree that you
understand the risks you may face! Press ctrl-c to exit otherwise "

echo "Listing all connections. Connected devices are highlighted"
nmcli con show 

read -p "Enter the name of the network you wish to modify exactly as
seen above and press enter " name 
nmcli con modify "$name" wifi.cloned-mac-address random

echo "Check that the cloned mac address is set to random" 
nmcli con show "$name" | grep "cloned-mac-address"

read -p "Your mac address has been changed and will randomly reassign
each time you restart your connection. Press enter to exit "

To use this script save it as something, like machange.sh and then do;

bash machange.sh