I cant seem to figure out how to trigger a function from my global script. The script is not linked to a node. I've tried everything I could think of, but I'm still stuck on this problem. Any kind of help would be very appreciated.
What is a "global script"?
If you mean an Autoload, it is a node just like everything else, and you call it the same as anything else. Either you use get_node() or you set it as active in the project settings and call it.
GlobalScriptName.my_function()