Hey guys. Just a really simple question. How would I make text appear in a text box from clicking an option button?

Also, say if these items that I want to be shown in the text box once selected had an assigned price, how would I make it produce the total in the text box?

This is a college assignment, just so you don't all accuse me of cheating of something, it's nothing too big however so I thought you could help me.

Thank you