To earn money with bitcoin you can do some works if a person needs help with something or just look for a job you might have luck finding one here in this forum.
Just buy Bitcoins at a low price and save them for a while. When the price goes up you can sell them at a profit. It can take a while before this happens but you just have to wait it out.
Trading is good way but you need initial capital and decent knowledge of the subject to earn money.,