Auto Populate a text field on selection of a lookup field

Hi all,

I am new to Microsoft Dynamic CRM 2016. I have an entity Project, i want to display a lookup field of Projects in Lead along with a text field for Project Country. What i want is when i select Project from lookup field, the project country field automatically gets populated with project country value. But i have no idea how can i do this CRM? If any one can give suggestion or give help then please.