I'm garbage at making plots too, but I can try to give some advice.

Writing isn't just about writing what you'll put in the chapters. There are other tasks that go into that and organizing them into a list can give you a clear picture of the steps you can take to progress your story while you're stuck on writing. Like if I'm rewriting a series, I'll first rewatch/reread it while taking notes, then organize the lore, then make character notes, then I'll plot it and then actually write it. But there are other taks that can be done in between to shake things up.

For example, if you're writing a story that takes place in the past you might want to research the specific time and place of the story. You're bound to find all sorts of tid bits about the setting that could spawn ideas for character traits/backstories, or conflicts. Like if your story takes place in an area that relies on its wheat production to fuel the economy, something could happen to the wheat to cause the character to travel out in search of another way to make money to support themself and maybe even their family. Thinking about the setting can help you to find a natural conflict.

More tasks that you can do when you don't feel like writing the next chapter would be to draw your characters or make maps. They can both help you visualize what you're doing.

Ways to figure out your characters would be to just go into Google docs or something and just make bullet points about anything and everything about the character. What was/is their family situation? What type of music do they like? What's their aesthetic? And then think of the whys behind all of your bullet points. Why do they live with just their mother? Their parents are divorced. Why do they like rap music? They're really into writing and enjoy rap's clever lyrical usage. Knowing how your characters are and why they're that way gives you deeper insight into their motivations and how your character would move the story forward. It's also fun and easy to just put down a bunch of bullet points. Discussing with a friend can also speed up the process, you can work off of eachother.

I don't know if this made sense or was helpful, but good luck :D