Crown top or bottom, left or right wrist is totally up to the user, it's configurable in the settings. It probably helps from a useability standpoint somewhat if people wear the watch with the crown towards their wrist and speaker and mic facing towards them, but even that isn't strictly necessary.
No correct way - just personal preference. At least with the Apple Watch you can change it!
I usually wear the watch on my left wrist with the crown on the left side - this was to stop the buttons being pressed by my cycling gloves (was annoying) - since breaking my left wrist in a bike crash its more comfortable on the right wrist again with the crown away from my gloves. Hopefully in time the .5cm difference in the wrist due to inflammation with return to its normal size and I'll switch back.
Any which way you prefer. I'm a righty but prefer to wear it on my right hand (crown out). For weight training at the gym I switch to left hand crown in - I perform various wrist movements when I'm doing weight training that end up pressing or turning the crown and messing up my volume or summoning Siri. I've also seen people wear it around their ankle but I'm not a fan