Starting off, if you want to earn revenue from ads, you would have to enable your account for monetization (ticking a box in your Youtube account and agreeing to the YouTube monetization agreement).
Next, connect your channel to an AdSense account (a program to display ads with your content).
Next, review ad formats and video criteria. What Youtube deems to be "advertiser-friendly" videos (for example, no violence in your videos) are allowed to be monetized. Also any BGM (background music) used in your videos must not break any copyright laws (how some portion of a game cutscene are muted, this is why)
Next, choose the videos you would want to be monetized.
You would need a substantial amount of videos to make a living. With an average 100 views per day, you would make about $100 in a year.
Hope this helps and more importantly be yourself. glhf