Your trading objectives, the amount of time and effort you devote to trading, the trading tactics you adopt, and your prior experience will all influence your path to trading success. Whether you establish your tactics or use someone else's, it will most likely take you 6 to 12 months to develop enough consistency to start seeing regular monthly income (though this varies).
That is if you practice for several hours every day systematically. Many people will take longer; a year is not out of the question. Make sure you're financially prepared and don't give up other sources of money until your trading earnings are sufficient to support you. Even so, having numerous sources of income is usually a good idea.