Just make sure you post 4 posts a day. If you post more than that, the amount of money you'll earn on each new post goes down 1/4th each time.
You can post more than 4 posts if you don't put too much time into them. Posting is a great way to earn followers, and their future votes will be worth more than the money you didn't earn with the post that made them follow you.
Getting followers is the most important factor in earning money here, because the more followers you have, the more people will see your posts and possibly upvote. Make sure to leave comments on their posts and upvote them as well. Once they remember you as someone who has helped them in the past, they'll be more likely to help you when they see your new posts.
Another good reason to comment is because people will upvote your comments. Some days I earn more money commenting than posting. Some days I don't earn hardly anything for my comments and posts. Some days you lose. Some days you win. The only way to lose for good is to quit, and the only way to win big is to keep posting and commenting.
When you earn Steem, power it up. That will make your vote worth more, and everybody here's main goal is to become friends with people whose upvotes are worth a lot. While you're a minnow, you won't have enough Steem for it to be worth cashing out anyway. So to put it to work for you building your reputation, and cash out if/when you need to.
There's a lot more technical stuff you can learn about Steemit, but if you follow that simple advice, you'll be fine.