If you have a home telephone number but want switch to a cell phone, you may be able to keep your home phone number as your cell number. Call your cell phone provider and tell them you want to transfer your home number to your cell phone.
You need to be ready to activate your new cell phone account and your old home phone number service must still be active to make the switch. Don't cancel your home phone service! Cell phone number portability depends on having both numbers live at the time of transfer. You can cancel the old service once you have been told that the new account for cell phone service is live.