請問那裡有和洋人小組聊天的地方？

You can try language exchange, which mean some 洋人 wants to learn a language you perfect and in return he/she teaches you English.

Where you can find it? http://hongkong.asiaxpat.com/personals/language-exchange/

洋人小組 it is one on one in this case
最好在東區 it can be anywhere you want as long as your partner agrees to it.
中學班 this would be difficult as they are generally adults