Can you play an instrument or sing? If so why aren't you earning money from this. Quite simply all you need is a cap and a place where there is a passing public. It is a lucrative business and one that many people make a living out of.
What if you don't have any musical talents? This doesn't not stop you earning as I know some one who is tone deaf but has a portable keyboard with a CD playing facility. He plays the CD with the keyboard switched off miming to the music that is playing. It is very effective in fact more effective that live music as he mimes the keyboard playing very well. It is only the very astute that realise he is miming, the rest put money in his opened keyboard carrier! This is not cheating, think back to the organ grinder who just turned a handle to create music, this is more above board than you think.
Well, you might be able to juggle, or mime this is another talent that people are willing to pay for as they pass you entertaining in the street.
There are of course laws in many places about who can and who cannot busk, even auditions for busking rights in some places. So you might want to checkout at your local police station on where things stand in your country or area.
Having busked myself many times before in London and Yorkshire it is hard work but pays well, well worth a try to help your finances a little.