Asia & Oceania

Seattle is a baby-city, in terms of size/density/age, I get that. So what should I expect when I travel to places like Beijing, Seoul, Tokyo, Hong Kong, etc? It seems difficult to even attempt to understand how massive these places are. Any advice when travelling to them?

I only know a little bit of Japanese, and wouldn't call myself fluent by any means, would I struggle in Japan at my current level? I've only completed the first two classes of the intro series.