Changing posts query for homepage slider

To be clear, I think I’d need to change how the slider query the posts to show, right? How can I do that?

Thank you for your reply Denzel!
But my problem was not to create a slider setting the images one by one, but using a more automated way like it does when in the customizer you set the slider only to show the latest blog posts.

I was looking, if that’s possible, for a code to add, I think, to functions.php to change the query that the slider uses to show blog posts, and changing it to a more personal query, like showing custom posts.

Thank you 🙂