What do cabin crew do?
We mostly see cabin crew serving food. Their real job is keeping the cabin in order and passengers at ease.
The real job
Before every flight, cabin crew hold a briefing, check the cabin equipment and welcome passengers. Throughout the flight they watch the cabin, stay in touch with the pilots and give instructions whenever needed. Service is just one part of the work.
Their training
Before starting, cabin crew go through thorough training: first aid, cabin procedures, passenger communication and drills for unusual situations. This training is renewed at regular intervals.
In turbulence
When the seatbelt sign comes on, they put the carts away and sit down and buckle up themselves. It's a routine precaution, not a sign that anything is wrong. They sit even in light bumps because walking around the cabin wouldn't be comfortable at that moment.
Asking for help
If you're nervous about flying, you can tell the cabin crew as you board. They help a lot with small things: explaining sounds, checking on you, bringing a glass of water. Requests like these are ordinary for them.