請幫忙改一下我寫的英文. 謝謝!

寫得不錯。基本句子和文法都ok，以下是一些少少錯的地方或個別寫法要更正。

That is one of the benefits of an international city.
Correction:
This is one of the benefits of living in an international city.

I must say that October is really the right time to come to Hong Kong.
Correction:
I must say October is really...
不需要用that的，因為這句本身是你的說法，寫成say that是表示某人「所說的」是....。跟句子的意思/用意不配。

After enjoying the German Fest; we will go to Ocean Park's Halloween bash night.
Correction:
After the German Fest, we will...
用after xxxing, yyy格式要注意相互的時間關係。這些事還未發生，所以用enjoying並不太貼切，改用一個無動詞的子句，反而更合情理。文法上after 跟xxxing你是沒有錯的。頭子句後是用comma(,)不是用semi-colon(;)的。

Disney的正式名稱是Hong Kong Disneyland，最少也要寫成Disneyland。因為Disney並不是那地點，而是公司/人姓名。迪士尼的全名是Walt Disney Company, 在美國還有一個Disney World呢！

I don't think you will have time to all of them, but we can go to those places that you are interested to.
Correction:
I dont' think we will have time for them all, (這句這樣寫法會似較像英文人的說法，你的寫法在某些情況也可以，但要這樣I don't think you will have time to go to all of them) but we can go to those places that you are interested []. 最尾的to寫多了，不用的。

Hi Jenny,

How are you doing? I'm glad to know that you will come to be arriving in Hong Kong next Monday. Since it is your first time in Hong Kong Being your first visit here, I am planning to take you on an unforgettable trip here for you.

To warm up First of all we will go shopping during your first 2 days in Hong Kong. Then we will go participate to in the annual Marco Polo German Bierfest 2010. You will be able to enjoy different kinds a variety of traditional German dishes , its from famous sausages, different kinds of dessert, snacks, and of course beers for sure! That is one of the benefits of an international city. You can taste food from different countries. Let your taste buds savor every moment in the international gourmet paradise like Hong Kong!

I must say that October is really the right time to come to visit Hong Kong. Everywhere is We are now preparing for Halloween as you will see it from every corner of the city. Many restaurants are being decorated with pumpkins and coffins, etc… After enjoying the German Fest, we will go to Ocean Park's Halloween Bash night – where you can visit the different themes like It has Terror Park, Pang Brothers' Child's Eyes, Zombie Hunt, Haunted Tales of Guangdong, Black Magic Academy, Fang Club, Museum of Horror, Burned Alive and more. We won’t get bored!

There are also some famous sightseeing places we could visit that you can’t afford to miss, for example, the Peak, Disneyland Park, Noah's Ark Hong Kong, Soho and Lan Kwai Fong area in Central, and 26 museums* in Hong Kong, just to name a few. I don't think you will have are having enough time to all of them for all the places as mentioned, but we can just go to those places that you are interested to in!

What do you think? I am looking forward to receiving your feedback on this.

With Love,
Zic *(I am not sure if we have as many as 26 museums in Hong Kong?)