Create margin account in a bank of your choice and transfer 5000 $, or a small figure if you cannot separate 5 grand from your expenses. Contact an online broker and set up a daily trading account so that you can start practising.
Identify a virtual stock exchange, there are a number of easy to play free stock trading games online that let you purchase and sell stocks in a virtual market. However, the gains and losses are tallied from the real stock exchange and they follow the real life patterns. The only thing imaginary is the money used in these transactions.
Go to VSE.marketwatch.com and play stock trading games based on Wall Street market. There are a number of other websites that offer free online trading games which can be used to tone up your skills.
Investingexperience.com offers games which are related to daily stock exchange traders. Wallstreetsurvivor.com and stocktrak.com are a few other websites that offer real time stock based games.
When playing these games, focus on those types of stocks where you want to actually invest in real life. Your investing patterns should also match your real time behaviours. For example, if you do not want to invest in a very high risk stock no matter how large the profit margin, you should not invest in that stock in the virtual world as well as it will give you a false idea of profits earned in the stock market.
If you have not formed an investment strategy yet practice on different strategies till you come up with a suitable investing strategies. Create an investment portfolio and work on it till you are certain that it will work in the real world as well.