1.go to www.textnow.com or search for "textnow" in playstore.
2.signup with your informations.
3.put area code of usa. I use 604 for me.
4.after you entered area code now you have to be fill captcha. after filling the captcha you will get your phone number now go to your profile and fill it and after filling check your email confirm your email adress.
now you are all set. you can now use your phone number.you can now send and recive calls & sms with your phone number free.