Best Video Editor

Hi you guys,
So I started a Youtube channel recently, and I wanna start making content for it. I've had my account for awhile, but I just created the channel. Anyways, Can someone tell me what the best video editor is? I want to add sound effects and musical intros and things like that, but I don't know where to turn. I know I had thought about using Final Cut Pro on my iPad, but I think it might be easier just to use my iPhone. I know there's iMovie, but I don't know how to add the things I want to add to the videos. So if anyone can either point me to an alternative video editor, explain how to use iMovie for what I want, or point me towards any resources, That would be very much appreciated. I want to make my content the best it can be, but I wanna make sure I'm using the best software I can. Thanks for any help. All the best,
Lesley.