If you are newbie then you need to keep posting, and then one day you will reach a higher rank. When you have a higher rank you can join signature bounty.
But there are lots of different bounties, you can do twitter, blog, translation or video.
but its not easy to rank now,because of merit system even if you post alot still you need to attract people here about your post and from then you can gain merit each,so for a newbie like OP he must learn social media campaigns though it requires many subscribers and real friends still its a big means of earning because you can join as many as you can