hi, I am planning to go hongkong on 27-30apr, advise on what I should wear?

I just checked the weather records of the past four years. It rained a lot in late Apr. which may ruin your trip at Disneyland. If you don't mind, change your travel plan to early Apr. The temp would be comfortable then and the cloudy days would be the majority. You can bring long-sleeved shirt, light jacket and jean and light raincoat in case.