My spoken English is not very good now, so I can't speak it Now I want to be a merchandiser. I wonder if I can learn English while working.

Yes, you can choose the kind that works during the day and studies at night. It's a little difficult, but it will be very helpful. I have a friend who also does this job, and now he is studying while working. She said it worked well. You can sign up for a training class. If you are in Hangzhou, you can visit Hangzhou New Channel!