You can't really mine Bitcoin unless you have ASICS, even then you need some connections in China as they have most the suppliers of machines which mine efficiently.

As for steem, i'm confused myself and trying to figure it out! will let you know as soon as i know more.

If you want to mine anything (to convert to bitcoin), try mining ethereum or siacoin. They are profitable to mine using high end Graphics cards.

Let me know if you have any other questions!