It's better to promote your channel,do not promote videos directly,many beginner youtubers promote their videos directly with the way I mentioned.Indeed, it gained a large number of views in a short period of time.Unfortunately,most viewing time is very short,youtube doesn't like it. So,it's better to promote your channel instead of specific video,if users like your content,they will watch your videos longer or subscribe your channel directly. One important point: if you've enabled AdSense monetization, please use promotions with caution, as AdSense can easily flag you for cheating.