You either start with first game or 0, I kinda recommend playing first one since playing it after 0 can be annoying since it's a PS2 game in its roots and 0 is modern game but it's your choice.
I played 6 then 0. Not ideal lol. 0 is awesome, also a good place to start chronologically. It might be better than the others but it’ll also set the tone as to whether or not you’ll like the entire series so might as well start at a high point
new smilie ^
its much better than the rest (except for the fact that only touhou fans really understand it and im not a touhou fan and yes its bad apple thats like the testing thingy
)