RE: What does this Number mean behind the steem user name ?
Just to add, as I'm finding.. (I'm new here too.)- there will be comments that you post which do not get up-votes or reply's. That's normal. It takes time for things to get rolling and your reputation score to increase.. but be active. Up-vote for what you like. Make meaningful reply's. Being among first to curate (up vote) posts that you like from high level (that #) member's will help you most in return and you'll learn from their contributions. I've heard that down voting can hurt you so use very sparingly or not at all. (watch for guides & read the white paper when you have an aspirin handy) As your # rises, you can help new "minnows" build their reputation as well by - clicking that arrow. Be genuine, and post content when you feel you have value to offer. You'll be one of the future "greats"!