It's no big deal. The bank will either give you the form to fill out, or ask you the questions and fill it for you. Mostly just identification stuff (name, address, ss# etc) and a brief explanation of why for you either want this much cash or have this much cash.
One day I was going to buy my first new car, and the POS bank wanted to charge me for a cashier's check. So I said FY, give me 16k in ca$h. Only took a few minutes to get the form filled out.