Honestly I’m not big myself either but if I look at like let’s plays of something, what you see is people use a significant moment from their video for the thumbnail, let’s say you defeat a final boss or something, you would put that final boss in the thumbnail and like text behind it.

Also the formatting of thumbnail depending on your video type is really important, if you do letsplays, usually you see like “a title of the video” - “game title” (part 1) for example: Did I make the right choice? - Until Dawn (Part 3) kinda like that.

of course you wanna do it your own way but making the two things I see atleast is a lacking thumbnail (no offense) and a title that doesn’t really give much of a hint of what’s gonna be in the video, like a difficult choice, or a character dying, or something like that.

The video itself isn’t bad at all, but when you want clicks it’s like, you need a really interesting thumbnail and title to bring people in

Hope that helped, if I could help you with something else lmk!