need help burning dvd-r

[toviolent]

This might be off the topic but Im new to this burning thing I use recordnow max to burn my dvds this is the first time Im going to try this Ok I got a dvd movie and I want to back it up with dvd-r can I just make copy using make an exact copy I heard that dvd-rs can only really record 3.9 or something and not 4.7 so will my dvd fit on dvd-r the dvd is friday after next I just want to make a exact copy can I do it? Thanks in advance