AutoTranny Filter & Fluid ???? 2003 Frontier

I just bought a 03 4 cylinder, automatic tran with 65 k miles on it. I see that there is a drain bolt on the tranny pan. Is there a filter that needs to be changed?

Also, anybody using synthetic fluid? Do you like it? Can synthetic and regular fluid mix or do I have to do a power flush to get all the old stuff out?
Thanks