What ever you do, don't start with dubstep

I think a very breif rundown of a few seconds tends to work. You can watch most Mr Beast videos and he does like, 5 seconds of hard explaining what's about to happen, and that tends to be more for seo than anything else. I know Nick Nimmin and others used to say to put right at the front what the video was about, because YouTube and Google would scan the first 30 seconds or so of the video to determine what the video is about. If YouTube can determine if you have copyrighted music, swearing in the first 30 seconds, and can also auto caption your videos, then it's no doubt listening to what is said and shown in the first 30 seconds. BUT you don't want to stuff your intros or you'll lose your audience because if your video is too long to get to the point, most will leave, the vocal ones will say "video starts at" in your comments so people can avoid your intro entirely.
I mean really, just watch any of TubeBuddy's intros, see what they do with their videos

it's a short snappy intro, or gets right to the information straight away.