I am going to have an operation on bunion. I work standing all day. Would I go back to work right away. After surgery?

No. After bunion surgery you should not be standing for long periods of time or sitting with your feet hanging down. This will cause you to swell more and take longer to heal. It will also increase the amount of pain you would experience post op.
Work . I would not advise that if you were my patient. Having said that some patients simply cannot take time away from work. Speak to your surgeon and go into this with your eyes wide open knowing that you will have , at the least, extended swelling.
Probably not. It may depend on what bunion procedure is performed, but it will be several weeks until you are able to put on an enclosed shoe and continuous standing will increase post op swelling. You should talk to your surgeon about how long you will be out of work.