I have delivered a celebratory speech more than once in my life. But the most memorable speech was at my aunt's wedding. I was the maid of honor and there were a lot of older people and some people with kids. So I knew that I had to make it pretty short, but not too short that it didn't seem thought out and meaningful. My speech, from my POV, I'd say was pretty good for being like 11. It was probably a solid 3-4 minutes with good eye contact and an appropriate amount of jokes. I was 11 years old, just learning how to properly write essays or whatever at that time, so I began with three things I wanted to express and how I was going to introduce myself and why I was giving the speech. Overall it was good, I mean people laughed at my jokes and seemed engaged for the time being and my aunt and uncle absolutely loved it.
That's really cool that you were able to do that! I would have been really nervous to talk in front of all those people at that age.