The word "well" in your sentence is an interjection and it is just there for effect. You can take it out and still have a good sentence. Sometimes people say it when they are trying to end a conversation or change the subject of the conversation. Also, it could mean, "I know that what you are doing is a chanllenge, and you may not succeed, but good luch anyway."

 

When we say, "very good luck," we are wishing the person the very best luck that he/she can have.  I hope this helps.

 

Carla