RPG game (crosshair) HELP!

Helo guys, this is my first post here, and I would like help on something… I’m doing a rpg single-player game, and it is first person, like skyrim, and I ran into a problem, I need a crosshair to the game, but I would like it to interact as well, not just appear there with an overlay scene, I want the sort of thing like when you pass it near an item on a table, it writes the name of the item and offers the option to pick it up, and when you are near doors it shows the name of the house and option to enter… I really need your help, because I have no idea on how to do this…

Thanks already, and sorry for any language mistakes, I’m brazilian…