I played Like a Dragon first, and found it to be an excellent introduction to the series. And I know a lot of people say to start the mainline games at 0, but personally played 0 last and was glad I did because it makes a lot of references you won't get if it's your first. Also, it's really tough going from 0 to Kiwami 1 because K1 feels super dated.
Sack to crack, going to town