The number after your name is your level of reputation within Steemit. I'm not sure exactly how the number is calculated but generally speaking, positively received activity is rewarded with reputation. I think the scale is logarithmic. It is possible to make money here in rewards for creating content that is well received by those with a vested stake or Steem Power. Their votes award SP and SD (Steem Dollars.) You can also earn by voting for other people's content but you ideally need some SP in order to what most people would regard as meaningful rewards. Still, every bit helps! ;))