How to fix two meshes crossing each other

I am completely new to Blender and I run into problems constantly haha! So far I have been able to fix these problems by watching a looot of tutorials, but now I’m stuck!

I’ve tried making a pentagram, but I have no idea how to fix the mesh crossing everywhere. Is there anyone here who could be so kind and explain how I can fix this or recommend a tutorial? Or maybe has a better way of doing a pentagram? :slight_smile:

you could try Boolean, but make sure faces are not overlapping, afterwards you’ll flatten avery faces that are supposed to be on the same Z level. Maybe share your file: