How to be successful on Youtube is simple, but it's not easy. It basically comes down to a handful of things...
You need to be putting out content consistantly. Depending on your video topics and niche that can very but at least one video a week, ideally 2-3.
2. Quality Content
You need to make quality content. Quality is subjective. You don't necessarily need the best production value, the best video, the best editing, but if you're doing something educational or information based the content needs to have value.
Youtube is a longterm game. While you may wind up having some success three weeks in, plan on doing this for 1-2 years with next to no results. Unless you go into it with that mindset you won't succeed because you'll quickly grow frustrated with the slow growth and no money.
4. Be Authentic
There's way too many people out there putting on this facade of this amazing life they live or all this money they are making. Most of it is non-sense. People appreciate authenticity. Heck there's a reason people watch Youtube either in addition to or instead of television. Just be yourself and be authentic and you'll connect with people.