Rhylee, I suggest that you explore the various concepts of magic in a bit more depth before you dive head first into such practice. If magic were a science, you would have to study chemistry and physics and other such things to make anything happen with them, wouldn't you? Magical concepts are much the same.
To that end, as others have suggested, manifesting such things physically is not possible but in a spiritual sense it may be. That is open to individual interpretation as well. In some schools, such spiritual interaction is purely an act that takes place within the self. Thus, if you dream of him, in a way you have already manifested this character within you.