Investing is a long term business. First you need to know how long you going to be in this business. To setup this business, you need to have capital and you need to use your capital wisely. 
Let say you have $10,000 and what you want to own? Allocate 3-5 stocks and you do not need to buy all at one time. Why? You need to look for good stock and undervalue ones. Is there any now? 
There are still good and undervalue stocks. One example is GOOGL, Morningstar fair value is $154....