You'll probably find yourself more relaxed around 10-20. It all comes through experience. I find I get more comfortable in longer recording sessions. The first 10 minutes a feel super awkward, but the more you talk to yourself out loud, the more you get used to it. Salma was saying a good way to overcome that is to make talking to yourself out loud a habit, that way you feel less strange about it.
You could always pretend you're talking to a live stream... OR do a few livestreams. You basically just want to relax into talking to a camera.
EVERYONE is awkward at first, check any big successful YouTuber's first videos and they're always shy. It's simply a matter of time and experience and repetition. Do it often enough and it will start feeling like second nature