how would i get to wuhan from Yiwu City, and the cheapast way

There are direct trains between the two cities and the price varies from 112 to 208RMB depending on different seats. If you want to know more detail information, you are advised to search in the Train Section on this website.
Or you can take the direct bus. The buses can be taken from Yiwu Binwang Bus Station at 17:20 and the fare is around 180RMB per adult.

How can I go by air-line from Myanmar to the city and then how much I need to spend money ?

Go to Rangoon to catch a flight to Kunming and then directly fly to your destination. As the air ticket fare varies from time to time, it is hard to tell the general cost. You can search the cost according to your departing date on the flight page in this website!