Active candidacy means you were not hired. That means that even if the client wanted to pay you,(and they probably do not) they can not pay you.
never ever do any work until you were actually hired (not just had a candidacy)
you know now you were hired when you receive an actual offer through Upwork and accepted it, and the job appears in your "my jobs" tab either as an hourly contract or a fixed price one with a fully funded milestone.
You will not be paid for this work.
This is a good thing.
This learning experience will help you to focus your mind and encourage you to learn how to use Upwork.
Each time that you work for free - doing projects and not getting paid for them - will bring you closer to an understanding of how to use Upwork properly. You will then begin to get paid for your work.
Well you shoulnd't submit the work. If you had thought just be prepered for next time to don;t fall so easy. there are many scammers around that will try to have their work done for free. It has happened to me too.