Let me give you the same advice I gave my children on their first flight.

Flight Attendants are human beings. If there is reason to get scared, they will be just as frightened as the rest of us.

The big difference is that they have flown often enough to know that the sudden difference in sound that the plane is making is normal and that the bumps being caused by turbulence are routine.

Any time you think something is wrong just take a look at the closest FA. If he/she is not turning pale and gripping the seat rest until his or her knuckles turn white, you know there is nothing to worry about.