Father’s Retirement Speech

So my father will be retiring in 6 months. So just wanted to prepare a speech for his retirement. I need help for narration as i feel there are so many good writers in GV. So my questions are how i need to write this type of speech, how many minutes it should be on an average, and also please recommend some books for narration/script writing or any videos on that.

BTW Chatgpt is not helping me!!!!