Yes it is possible to live with just one lung.
Both lungs are best to provide you with enough breathing capacity and give you enough energy but if you have to have one lung removed then you can live with just one lung.
You must have at least one lung to live and cannot live without both lungs but you only need one lung to be able to live and breathe.
As long as you have at least one lung left you can live.
If you have a diseased or injured lung then there is a surgical procedure that can be done to remove one of your lungs.
The surgical procedure to remove a lung is called Pneumonectomy.
It's also possible to have a lung transplant that you can get from a deceased person or someone who wants to donate a lung to you.
Most times though the lung transplant will come from someone who is deceased.