你们好朋友！你们好吗！ (Is this correct?)
If I want to say "hello" and "how are you, friends?" to a GROUP of my friends is the way I wrote it correct?

Please correct me if I'm wrong in the following:

你好！ = "Hello" (only to one person)
你们好！ = "Hello" (when saying it to a group)

你好朋友！ = "Hello friend" (but this CANNOT mean "hello friends").
你们好朋友！ = "Hello friends"

你好吗？ = "How are you?" (only to one person)
你们好吗？= "How are you?" (to multiple people)

If I understand correctly there isn't any plural form of verbs so there must be a number placed in a sentence to show more than one of something. However, when speaking with/about people you only have to use 们 in order to show that there is more than one person.

Thanks in advance for your help!

Question

你们好朋友！ 你们好吗！   (Is this correct?)
If I want to say "hello" and "how are you, friends?" to a GROUP of my friends is the way I wrote it correct?

Please correct me if I'm wrong in the following:

你好！  = "Hello" (only to one person)
你们好！  = "Hello" (when saying it to a group)

你好朋友！ = "Hello friend" (but this CANNOT mean "hello friends").
你们好朋友！  = "Hello friends"

你好吗？ = "How are you?"  (only to one person)
你们好吗？= "How are you?" (to multiple people)

If I understand correctly there isn't any plural form of verbs so there must be a number placed in a sentence to show more than one of something.  However, when speaking with/about people you only have to use 们 in order to show that there is more than one person.

Thanks in advance for your help!

Answer

你们好朋友！ 你们好吗！ - × should be 朋友们! 你们好吗 !

你好！ = "Hello" (only to one person) - √
你们好！ = "Hello" (when saying it to a group) - √

你好,朋友！ = "Hello friend" (but this CANNOT mean "hello friends"). - √ or 朋友你好！
你们好,朋友！ = "Hello friends" - a little strange,  better say  '朋友们，你们好', or '你们好,朋友们', or just '你们好'

你好吗？ = "How are you?" (only to one person) - √
你们好吗？= "How are you?" (to multiple people) - √

Answer

Your understand is right. But there is a little problem in second group. I mean chinese. You wrote "你好朋友“ and ”你们好朋友“ In chinese,  punctuation is really important when we use them. so if you write”你好，朋友" and "你们好，朋友“ . it will be better than now. if you wirte " 你们好朋友”， someone could think that it means you are good friends

Answer

"hello (to a group of people)" = 大家好

"how are you, friends?" --  Chinese people don't say "how are you" in the greeting, it's impolite