There is no magic formula to YouTube and there is no secret that only "successful" Youtubers know about.
"How to grow my channel?" questions like this are too general and this question has been asked and answered lots of times already. Since the answers don't really change, these threads get locked. Otherwise the forum would be full of them.
Find out how to promote your YouTube videos the best you can, get and share top techniques & tips with others and learn how to drive people to your channel, gain new subscribers and build a bigger and better audience.
Learn how to grow your channel using marketing strategies and SEO techniques that help your videos rank better in YouTube's search results gaining your videos and brand more exposure maximizing your views, engagement and video sharing.