Shanghai is a modern city, it’s known as the Shopping Paradise.这句可能有点错误。这句话有两个主语，虽然主语是一样的。但最好中间添加连接词如and，或改为从句形式，如
Shanghai，which is known as the Shopping Paradise， is a modern city,
文中使用的Shanghai比较多，可用it代替。许多除了用many以外，还可以用lots of、a lot of、much（不可数）、 numerous、 a great many、a large number of等。
If someone comes to Shanghai, he may go to the Oriental Pearl TV Tower.本人认为此句比较像中国英语，像用中文直译英文。本人认为可与前一句联系，写成：
Every year, many visitors come to Shanghai to visit the Oriental Pearl TV Tower and other tourist attractions.