What happens if i upvote my own post and comments often and What is the disadvantage?

helo mates, is it right to be upvoting my own post or comments?
Since i joined steemit if i make a post i see that i ave already have an upvote for it which is my own vote and thought is was auto default, not knewing that my autor upvote post check box was marked. so know i begin to notice this from some people fresh post that has no upvote on it. then i decide to check and find out that all my previous post was on auto upvote, has it been affecting my account, Thanks as u reply me with informative idea.