Mobile phone numbers are not given out. If someone doesn't want you to find them, there cell phone number is not listed. There are sites you can pay a fee and they will give you the phone number. But for free it can't be done.
There are lots of sites now that a certain number can be found but it really has a fee. You may try this one http://www.whosecpnumber.com/ or you can also search in Google if you don't want the service offered.