Hey there, Tina! To speak to a live person you can call customer service at 888-322-1122. Though we can assist you as well if you wish.
Are you getting any specific error message when you try to activate the device here at https://activate.virginmobileusa.com/#/your-device?
Is that a Virgin Mobile iPhone? If not, you will need to check eligibility and get a compatible SIM card here at https://www.virginmobileusa.com/plans/bring-your-device.html.