I'm new to Coding,and i need help on a couple things.

*How to make doors, and how to make them open and close when you walk into them.(i have the icons for each phase already,i just dont know how to use it.)

*How to talk,attack,how to make NPCs move,attack back,and how to make an invetory,and picking stuff,up and dropping stuff.

if anyone knows how to do any of that or where a tutorial showing this stuff is, please tell me.thanks for all the help