After 15 years in HongKong, I dont think I've ever seen the game played regularly in any outdoor venues (like you see Chess played in many cities).
However, I know that the city is full of Go clubs where people join to play and learn in a very nice environment. Perhaps you should consider joining one of these clubs...At the very least, drop in and ask; they should be able to point you to the right place.
I know of 2 clubs in Causeway bay. I pass one of them on a weekly basis. The interior is large and usually full of people sitting and playing intently in a clean and nice environment. I know they speak English as I've been inside and enquired about lessons. Drop in and ask them.
I'm sorry, I dont know the name of the place but its located on the corner of Haven & Leighton. If you get to that corner, you cant miss it - the place is covered with Go posters.