Hi, We are moving to Kunming this summer. I am looking for someone who sews and hangs curtains. do you have recommendations for someone? Is there a chance to find someone who speaks English?

There are companies doing this. They are located at several places but a cluster of them can be found at the north-west corner of the junction of Guangfu lu and Xingke lu.

As Lemon lover says, there are lots of companies doing this, mostly small family businesses, but some are larger. You should have no problems finding people local to where you are going to live. The larger businesses have many sample sets already made and hung in the showrooms, which is better than trying to choose from a sample/pattern book.
Usually when they quote, this is for the made item. This usually comes with tiebacks. Some curtains are 3 layers, including nets, which often come as part of the set. These places also fit curtain rails, which start at a very low price.
Be aware that all the curtain places we visited only do full drop curtains as that is the width of material they use, such is the market. We got some shorter curtains made, but had to pay for the full drop. We could not get two drops as even the short windows here are 1.5m.

Thank you very much for the answers. Will they come to my apartment to take measures before sewing??

They usually do, and they will also deliver and hang them for you.

Is there a chance to find someone who speaks English? If not, how do I communicate them ?

Very unlikely finding anybody in the industry to speak English.
So use hand and feet or find somebody to accompany you. (Some people on this forum offered services like that).

Two more points to note.

One, they will expect you to haggle, also shop around, to get a feel for prices, and make note of the materials used as it affects price.
Two, buy your self a cheap set of step ladders, you can get them at any big supermarket and sometimes there is a neighborhood hardware store that has them. The reason is that most trades people, even those who need ladders, don't bring them. They are always useful as most places here have 3m ceilings.

Thank you for the good advices and the help.