anyone

You can use "anyone" when you want to direct a question at a whole group of people:

Does anyone know how to fix this?

Has anyone seen my cell phone? I think I left it laying in here somewhere.

(an alarm) goes off

The verb that describes an alarm making its alarm sounds is "go off". Car alarms, fire alarms, and even your alarm clock at home all "go off":

I was in class when the tornado alarm went off.

I usually wake up before my alarm even goes off.

Other things that are similar to alarms also "go off":

When he said that, warning bells went off in my head. Why did he want to know about that?

Did you hear the gun go off?

His temper is like a time bomb waiting to go off.

Hey

You say "Hey" at the beginning of a sentence in casual English when you want to get someone's attention. For example:

Hey, Hitomi, can you hand me that box over there?

It's common to say "Hey" before you ask someone a question, or when someone has done something that's wrong or unfair:

Hey, you're taking up the whole bed!

Use "hey" with people you know or are familiar with. When you're talking to people you don't know as well, "Excuse me" is more polite.