How to make a Ontouch Quest with Text GUI?

So I am making this game with my friend, And I need it so this alien gives us a quest, I want it so you touch a item, Come back, And you completed the quest, I also want it so you have to touch the item for it to work, And I need the quest part to come in, I am a scripter (I have scripts in a document) So I need help on how to make it so you have to touch something and come back to complete the quest, Also so that you don't waste your time please explain the script to me so I can better understand it, I was thinking something like

I put a script in a block that checks to see if block is ontouched, And if it is not then don't do anything, But if it is then complete the quest, Also with this can I get a text GUI, I need a Text GUI to pop up like the guy is saying something, Sorry if this question breaks any rules.

Try using Remote events or remote functions so you can communicate with local scripts in the guis.