You need to pass a certain threshold per vote - I believe 0.001 SP - before it counts. But as newbie, you will hardly reach that threshold. Better to post good articles the first few weeks and do a lot of good commenting and upvote comments, not articles.

Convert all STEEM earned into STEEM Power. After you reach about 100 STEEM power, your vote on articles slowly starts to count (but still in the 0.00x range).

Hope this helps.