I am sorry I want to ask if you want to make the unity which the collision to a first-person role of an object (or within a certain range) will pop up pictures with text, how to write such a script?!
You would probably add a collider. Set it as a trigger. Then use an onTriggerEnter onTriggerExit to throw a boolean variable. The onGui function would check for the variable and post a message. Usually, when you have to ask such a vague question, you need more experience before doing such things, so you should probably just keep going through tutorials for a while.