Hi @Madeline Baia ,
What is the make and model number of the landline phone?
Is the phone connected to the telephone cable coming in from the street or to a modem which also has the internet connected?
''If connected directly to the telephone cable,'' try plugging in another known working corded phone and see if that works. If still not and it is the only device connected to the phone line in the premises then there is a problem with the line or the phone service provider's equipment. Contact them about the problem and tell them what you have tried.
''If the phone is connected to a modem'', does the internet work and have you checked the phone settings in the modem using the modem’s user interface from a computer?