1. 第一句跟第二句的意思是一样的，可以省略其中一个。

2.通常演讲前面可以加个“Good morning / afternoon, everyone.等开场白，演讲结束加个结束语，如That's all. Thank you.

3.根据你要表达的大概意思，我帮你修改一下语法方面的问题,没有使用很多从句，基本是保持原来的简单句式。

4.一般按照匀速的话，表达出来，大概就一分钟左右吧。

Good morning, everyone. It’s my pleasure to introduce myself to all of you here. My name is XXX. I am a fanciful girl who always have many wonderful dreams. Sometimes, I would like to travel around the world, sitting on the clouds. Sometimes, I want to become a witch so as to steal the spell of black cat. Sometimes, I want to have the same speed as the vampire.

I have hundreds of dreams, most of which probably won't come true. However, I also have a very realistic dream. I want to be invigorating, like the pianist. (其实精力充沛跟钢琴家没有什么必然的联系吧？ 如果是要表示充满活力的，可以用energetic ，更简单点）

I have been playing the piano since I was little, hoping that one day, I can have a concert held in Provence. I am also in the hope that one day, I could own a piano which is the same as theirs. But my parents always say," Do not think about irrelevant things. Study is the most important." What they say really discourage me.

I hope my parents can give me more free space. They should allow me to schedule the time by myself, which can make me mature. And this is my biggest wish. I do hope someday in the future it can come true.

That's all for my speech. Thank you for listening.