Blueprint to Level Blueprint help


im having problems im still new to blueprints i have done all the tutorials and read most of the documents but im still having issue. im trying right know for my UMG to talk to my level blueprint im trying to make it so then when you press start to tells the level blueprint to start doing what it need to do. so i have it right know the level blueprint with a custom event at the start and im trying to make the UMG blueprint to trigger the custom event. the only way i have gotten a blueprint to talk to another what to us a spawn actor. i have tried casting but it just fails every time but i really need these blueprints to talk with one another i don’t know if im using the casting wrong i did try making a variable and made the variable type the blueprint i need and then call but for some reason that did not work.and also every time i try to references the level blueprint in my UMG menu and try and save it says the level blueprint is in another map (i only have 1 level)
to show you an example of what i have tried

like i said im still new at this help would be much appreciated.