I just wanted to watch the new series from Rohan because it also says that there are 4 episodes but when you watch the first episode it says at minute 2:19 that it is episode 16? Do I have to have seen anything before except Jojo part4?
Based on the manga, the chapters are numbered
https://jojo.fandom.com/wiki/Thus_Spoke_Kishibe_Rohan#Volumes