You can get the password of a certain WIFI in two ways:

1. Ask the owner of WIFI, and you can use it when he tells you the password.

if it's a hotel, ask the front desk. If it's from a hotel, ask the waiter inside. If it belongs to the company, ask the staff inside. It's personal, just ask him himself.

2. download WIFI cracking software to crack passwords, such as WiFi companion and WiFi master key.

but not all WIFI passwords can be cracked.