First I want to welcome you to the forum.  I am sure there is a setting in the menus that will allow you to set the time that the display is on.  I would suggest the manual.  I went from a D3200 to a D7200 and the manual was my friend, as well as a handbook on the  camera.  There is just so many differences that I had to read them both, and I keep them handy...  It also helped me unlock options I had not considered.