What's the difference between "How many are you? " and "How many of you are there?" ?

I would like to ask a silly question but I'm really interested to know the answer. I, as an English learner and being an adult, what should I say "dad/mom" or "father/mother"? I wonder if I say "dad" or "mom", do I sound like a child? I remember some years ago a native English speaker told me not to say "mom" because that's what children say, according to him. So, I wonder if that's true or not.

What does "be on someone" mean? Also, I'm not sure if the collocation is "be on" or "be on someone". Context: A dad is complaining to his little daughter about his other baby daughter not helping pick up the mess. DAD: You know what? I have no tolerance for laziness. So if I see you being lazy, I'm going to BE ON YOU just like I WAS ON YOUR sister.

What does "be off to do something" mean? Context: I was watching a video where an English teacher introduces herself and talks about her background. At the end of the video she says, "You're already off to a great start by taking the first steps to learn a new language."

Hi, everyone! Just a silly question. When enumerating the things I'm going to have for lunch, breakfast, dinner, should I use "WITH" or "AND"? Example: - What are you having for breakfast? - I'm having milk AND/WITH cereal for breakfast. - What are you having for lunch? - I'm having fried fish fillet AND/WITH rice for lunch. If both "AND" and "WITH" are possible, what's the difference in meaning between them?

Hi, everyone. I found the expression "I have died everyday waiting for you" in the lyrics of the song "a thousand years" by Cristina Perri. I would like to know what this expression really means. Also I'm wondering how often you use this expression in English.

Hi, everyone! If someone interested in making friends tells me "I want to know your background", what kind of information should I share with them?

Hi everyone. In the song "the rose" by Bette Midler I found the expression "take the chance". So I would like its meaning, but I'm in doubt whether it means "take the opportunity" or "run the risk". Here is the context: "It's the heart, afraid of breaking that never learns to dance. It's the dream, afraid of waking that never takes the chance."

Hi, everyone! Could anyone tell me the difference in meaning between "to make a commitment" and "to give a commitment"? For "to make a commitment" I have this meaning "promising to do something".