How do i execute a script in singleplayer?

I want to be able to test script menus before i buy a script executor or something like that

go into the editor, place down a single unit, then double click on that unit and check player, at the top left go ahead and save it, name the mission anything. now go to C:\Users\yourusername\Documents\Arma 3 and your mission will either be under missions or mpmissions depending on what you saved it as, now simply put your script inside your missions folder. now go back into the game and click start at the bottom right and once your loaded in, press ESC. in the debug console type in, execVM "nameofscript.sqf"; and press enter, it will load the script.