You have several options:

• By posting good content, if the whales (big holders of steem power) are interested in it they will vote your post and and after a week some steem will be accredited to your account (50% of the earnings, the other 50% is accredited on steem power)

• By buying it with another crypto or with fiat(normal money)

• By powering down your steem power, this will "transform" your steem power to liquid steem in the lapse of several weeks.

• By using faucets

Usually there are some contest where the price is on steem or steem dolars.