Proofreading?

Hi Teachers,
Please help correct my letter if there are any grammatical mistakes. Thank you very much!

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Dear John,
How’s everything with you?
I am writing to tell you that I won the first prize in the debate competition last month. The sponsor offered me a two-week holiday which I can choose anywhere to go with a friend. I am so surprised that I want to share this exciting news with you.

I have been thinking where to go for a long time, I finally make up my mind to spend my holiday in Japan. As you know, I am a big fans of Japanese animation. I have been looking forward traveling in Japan for ages, and I get this precious opportunity now.

John, do you want to start journey with me? I know you are crazy about Japanese Cartoon, someone told me that there will be a large-scale cartoon exhibition in Tokyo national museum next Sunday, your idol, Mr. Toriyama Akira will also attend this event, you may take a picture with him and ask him for an autography by then.

Please let me know whether you will come with me or not.

Yours sincerely,
Mary