Amateur designer on the works

I’ve picked up photoshop for the sake of building creativity and made something like this (altho I followed a random yt tutorial to make this design). I seem to struggle with putting ideas into image, let alone making those ideas turn into a creative flair.

Whenever I feel stuck in conceptualizing a design, what’s the best way to get out of the rut?

Currently, I’m thinking of a new poster but I’m having a hard time turning it into reality.