what is the scope variable ???

• GLOBAL_WORLD: dimension specific variables that are stored with the game save
• GLOBAL_MAP: world save specific variables that are stored with the game save
• GLOBAL_SESSION: variable that is stored per Minecraft launch instance and is shared across all worlds, but not saved after Minecraft is closed

Variables per player can be achieved using entity NBT procedure blocks.

Please take a read of https://mcreator.net/wiki/variables.

Our wiki convers all common topics you need.

I also suggest you check our tutorials collection playlist on our YouTube channel which contains many examples and tutorials that can help you get started with MCreator: https://www.youtube.com/playlist?list=PLAeL-oIFIEngE6jRgFYeFMfuj8WQsO3Ei