I can't find the password for wifi network?

Well, we can't help you find a password. That's why it's a password. Whoever is providing the WiFi signal should know the password, but we aren't hackers, and we don't assist people in trying to obtain it nefariously.

Ask the person who owns the router that is supplying the WiFi signal.

If this is a router provided by your ISP, and you've never done anything to its setup yourself, the password may well be printed right on the router itself.

or if somebody set it up for you like a friend or people from the isp contact them

this is kinda like asking if we can give you your creditcard pincode..

If you have a Mac, open the Keychain application (Applications/Utilities folder..or search Keychain in spotlight). Find the entry for your wireless network, double click, the select show password. You will be asked to enter the computers admin password, then the network password will be displayed.

Just wanted to thank you, Sandman. I'm not a hacker as automatically assumed by some people regarding the OP's original question. My internet went down, and I'm not a technical person at all, but thanks to your helpful reply, I was able to get my internet/WiFi back online. Cheers!