Idea: Plan in relation to a specific story that you like
If I'm stuck on where a story should go, it seems to help to pick a similar story I'm familiar with and work from there. Identify the major scenes and ask whether I want to have parallels in my own story, and if so how I expect them to proceed. For example, if I were drafting a dating sim, I might draw on Doki Doki Literature Club, and in particular the first "phase" which seems more standard for the genre. Maybe there is a meet cute, followed by a brush with death (the unknown), followed by oh no here is the thing, followed by some kind of a resolution, followed by an ending. Doki Doki Literature Club is actually missing some of these because of what it's doing, but it has most of them. This has worked for me in practice.
This doesn't of course mean doing exactly what the example does. I can and often will decide not to do things like the example. This is not even a radical rebellion against structure; it's a necessary consequence of writing a different story. It's useful though to have a story as reference point, like knowing where I am in relation to my house.
I suspect it helps to know a formalized structure or five. For example: The Story Circle, Hero's Journey, Seven-Point Structure, or the Rule of Three. I've broken down maybe a dozen stories in the story circle and at least got familiar with the others. The formalized structures help identify what's structurally interesting or impotant. I'm not sure they're necessary for that, though.
I find a specific example more helpful than the formalized structure alone. The structures necessary abstract out most of the detail, but it's the details that inspire me. If I pick a specific story I like, it's way easier to describe how I want my story to match that or how I want my story to be different. I find ideas like the Story Circle so vague I can't get a grip on any of the specifics of my story. I need an example to plan in relation to.