If you’re looking to build your channel, then it’s worth doing right away. You can post live or pre-recorded videos; both work well for growing the number of people who visit your channel and subscribe to it. The drawback with recording is that you’re essentially starting fresh each time you post a new video, which means more promotion is needed. Once the initial buzz has died down, though, posting live will still help generate views on existing videos while also driving traffic back to them (just make sure they remain relevant!). If your goal is simply to grow an audience for content in general—say if you want more viewers or subscribers for all of your personal vlogs—then start sooner rather than later. It takes some planning and effort but pays off in the end!