I am traveling to Dalían on 24th of April. Which Type of clothes I should tale with me.

Currently, it is hard to tell the weather in such an early time, but only a general situation can be told based on the previous records.
According to the previous records, the average temperature is around 8 to 15C then.
For the air tickets, it is hard to tell the exact price, because you may get a large discount if you book in advance. As I know, the Air China, Shenzhen Airline, Southern Airline and Eastern Airline, so it is suggested to look for the price information on their official website.