What’s the first question new students usually ask you?
“Where's the financial aid office?” After that, “Do you think this is a good idea for my thesis?” I love that one. I can only speak for the programs in which I teach or have attended but no one expects students to walk in the first day of grad school with their whole thesis figured out. They were accepted because someone saw great potential in them and wants to make the effort to help them expand that into something really fantastic. And that takes time.