你翻译的不错。稍加修改就完全正确——
When I was a kid,I used to dream to fly in the blue sky.
And now,I start the dream of flying,I 【am/feel一般现在时】free.
还可以翻译为:
When I was young,I used to dream of flying in the blue sky.
And now,I begin to make my dream come true,flying freely in the air.
祝你开心如意?,