請幫我看看以下英文內容是否有文法錯誤?

The greatest pleasure in my life is doing what I like to do. Traveling abroad, visiting some popular places in Taiwan, enjoying delicious food and having a picnic with friends are my favorite ones.

I have been to more than ten countries, including China, Japan, Korea, Singapore, Thailand, America, Canada and England.

In Taiwan, Hualien and Taitung are my favorite cities where I can relax (myself) and admire(appreciate) the most beautiful scenery.
Relax 應有受詞，”欣賞”事物 appreciate 比admire 合適，因admire較偏向”讚賞”"仰慕”的意思。

On weekends, I usually have brunch(s) with my friends in nice and famous restaurant(s).
在多個週末裡，做的是多件事，後面的敘述應使用複數。否則文意上好似每個週末都在做同一件事，在同一家名飯店度過，英文習慣上，在複數的情況下，接下來的它相關的敘述也用複數。

Having a picnic is one of my hobbies. We share not only yummy food but also our joy(s) and (lives). Would you like to go on a picnic with me?
多個人的歡樂及生活應使用複數。

坦白評論閣下的作文單從"文法"而言沒有"錯誤"，但是某些句子的寫法/句式和內容的表達上跟"文語"的表達"方式"會有些"錯誤"或不合"英語邏輯"。以下只選出兩處作為舉例而已，由於全篇仍有不同的表達方式，請多參考其他人的意見。
1.
The greatest pleasure in my life is doing what I like to do.
這句以文法結構而言：The greatest pleasure... is "...."是沒錯的，只不過"doing what I like to do."這表達的"意義"便跟pleasure in life差不多同等，即是說你的句子就像以中文寫「人生最快樂的事便是做開心的事"，寫了一句意義同樣而重覆的字，以為是寫了一句有意思的句子。
[當然在某些語文或文化和修辭(詩詞歌曲)這寫法是可以的]

就像TOMING88修改你這句指出，其實這句似乎你是表示所謂的what I like to do是後面列出的"各處旅遊"，而不是一句"定義"。

4.
On weekends, I usually have brunch with my friends in a nice and famous restaurant.
這句亦是文法正確。按TOMING88給你的修改會是較為像英語人的寫法/說法。由於你這句的寫法中A nice and famous restaurant表示了你只會去"唯一/獨一/指定的"這間餐廳，每星期都必定一樣。從英語邏輯上有點不正常。當然世上是有人每個星期天都上同間餐廳吃飯的，你是這樣的話這句便很正常亦是正確的表達。所以我不會說這句有寫錯的地方，只是你可以留意這表達上跟讀者看來你所說的意思，除了表面的nice和famous是你你選擇的理由，是否可以進一步表示"為何你們通常在週末都在這餐廳進餐以說明為可這是"唯一"的"a"。

5.
Having a picnic is one of my hobbies. We share ...
這句以present participle開句你想展示你的文法功力本身沒問題，但是只可說"眼高手低"了，Having....後並不會"停""."的，而是要延續","下子句的交代. 另外We在這段中並沒有"主角"出現過，當然可能你心裏是想著"跟你的朋友們"的We，但文法正確而言，你必定是先說明We是指那些人後才能用"代名詞"，不要以為上段已經有說過have brunch with my friends便可以，因此句法邏輯上而言，上段或文章中的人未必等於你這段中跟你一起picnic的人吧(這用中文理解也應理解)。因此唯一嚴格批評你的文法便是這個We字，需要指明誰是We。

全篇內容而言，主題好像是說「人生樂事」，內容有點東拉西扯得不太平均，說旅遊的內容好像比跟朋友相聚多，高級餐廳聚餐跟戶外的野餐的內容對比太強而內容亦參差，另上最後一問句，可能你想跟讀者連繫，但為何單以邀請picnic作結，為何不是請問大家跟你去下一個旅遊目的地，或weekends加入的高級聚餐？其實還有另一種問句結束寫法：What is you would like to do in life that make you happy? 或簡潔地以文章的命題反問：What is your pleasure in life?

Hope you do well in your writing.

----The greatest pleasure in my life is doing what I like(......)Travelling abroad, visiting some popular places in Taiwan(and in other places, countries), enjoying delicious food, people, places and having a picnic with friends are my favorite(----)
---- I have been to more than ten countries, including China, Japan, Korea, Singapore, Thailand, England, (Canada and America).
-----In Taiwan, Hualien and Taitung are my favorite cities where I find (relaxation, recreation) and admiring the most beautiful sceneries.
-----On weekends, I usually have brunch with my friends in famous restaurants(----)
-----Having a picnic is one of my hobbies (in leisure time). (We are not just sharing the delicious food, people, places), but also our wishful joy and (occasions of great happiness in life). Would you like to go on a picnic with me ?

The greatest pleasure in my life is doing what I like to do, such as traveling abroad, visiting some popular places in Taiwan, enjoying delicious food and having a picnic with friends, for all of them are my favorite ones.
I have been travelling to eight countries, namely, China, Japan, Korea, Singapore, Thailand, America, Canada and England.
As to Taiwan, both Hualien and Taitung are my favorite cities where I can enjoy and appreciate the most beautiful scenery.
On every weekend, I usually have brunch with my friends in a nice and famous restaurant and also having picnic with them is one of my hobbies and we share not only yummy food but also our joy and life together.. Would you like to go on a picnic with me? Yip

We are not just share...