Nothing is free
Nothing is really free. The usual ploy is to promise something for free, but they want your credit card number for shipping or just for the record. Well . . . usually the fine print says that after a "trial" period (usually 30 days), you have committed to a subscription at a monthly rate. So, read EVERYTHING carefully. Then the option is yours. As a last resort, should you succumb and have "buyer's remorse", you can kill the charge with your credit card company. I think there may be a time limit of 48 hours on that.