To see a can in your dream, indicates that there is something in your past that you need to hold on to and preserve.
The dream may also be a pun on how you “can” do something. Don’t underestimate your abilities and talents.
To dream of an empty can suggests that you are contemplating some venture or activity which would turn out to be disappointing and a waste of effort. Don’t try anything unfamiliar for a while after you have this dream.