So, at the moment you and I are what the steem community calls Minnows. once you get enough rep you will evolve hehe.
anyway jokes apart, when someone upvotes, his voting power goes to the post. You will notice that when you upvote the figure barely changes or sometimes adds a 1c. this is normal untill you gain some steem power. you will start seeing steem power coming in after the first 7 days.

Reason is a post is online and editable for 7 days. people can upvote you in that period. after 7 days the post goes permanent on the web and there is no way to take it down. so be carefull what you post ;)

there are actually 3 ways to earn money here:

1. posting
2. comenting
3. upvoting

after 7 days the figure dispayed on each post is devided into 2/3 for the post creator and 1/3 for the upvoters and commenters.

Be careful who to upvote. you may want to look into upvoting people with a very high rep that get hundreds with every post.

hope this helps