Most Helpful Girl
I watch The Vampire Diaries, and only a few episodes of The Originals. I enjoyed The Originals, but I am going to watch them from the beginning after this last season of The Vampire Diaries is over. (April or May of 2017) mostly so I have something to look forward to because I really like the show, and I know I will like the Originals. 😁
You really don't HAVE to watch The Vampire Diaries to watch and enjoy the Originals, but a few story lines are in The Vampire Diaries so it could clear up questions or something like that. You are 15, so you would probably enjoy it because it's a young-adult drama. You could just see the first few episodes and decide if you want to dive in, but beware, there are 8 seasons.
If it doesn't look interesting to you, it's not a big deal because they are totally separate, I think.
Most Helpful Guy
The Originals is a spin off series and it's a separate show, meaning, you don't have to watch The Vampire Diaries for it. So far, only minor things in The Originals would require you to watch The Vampire Diaries, but otherwise, no. The pilot for The Originals was one of the episodes of The Vampire Diaries, more or less.
You can, but in my personal opinion, The Originals is superior in every way. The Vampire Diaries is more of a teenage drama, drama, DRAMA. The main characters aren't as interesting, the acting isn't as good, the plots are nothing compared to those in The Originals, and the list goes on. Klaus was the villain in The Vampire Diaries, in The Originals he is an anti hero.