In a word… Experiment!
No one play style is correct, nor is it best in every situation. For me personally (note, 5 years of trail and error to find what works for me, I have found that...
Close range: I keep moving. It keeps me tough to hit.
Long Range: I remain stationary. At long ranges, I find movement to be a hinderance.
If I know a player is around a corner for whatever reason (Camper, Ping Perk, Satcom, etc), I typically jump around the corner to confront them. The change in stance helps me to catch them off guard.
This game is interesting in the fact that play styles are not cut and dry. Some players find it better to do different things. There are some excellent posts on these forums in which people explain their tactics. One post that garnered tons of likes was created by an older player who played what would be considered a more "campy" style of game, but cited that it's what worked for him because his reactions were no as good as some of the younger players. It's a fantastic post if you can track it down, and I highly recommend checking it out.
Honestly, just experiment. Practice makes perfect. Nobody hops online and has the game perfectly figured out on day 1. It wouldn't be fun it that was the case.
Best of luck to you!