How do I get a free toll free phone number for free to go along with my regular cell number?
You can't have a toll free number for free. The point of the toll free number is so people can call a business without paying for it. The company is the one who pays the bill.
To get toll free to go along with your number, you will have to talk to your service provider. This is because you will have to pay for the calls made to your phone on toll free since the callers won't be charged.