Define and write down the conditions under which you'll enter a position. "Buy during uptrend" isn't specific enough. Something like this is much more specific and also testable: "Buy when price breaks above the upper trendline of a triangle pattern, where the triangle was preceded by an uptrend (at least one higher swing high and higher swing low before the triangle formed) on the two-minute chart in the first two hours of the trading day."

An online brokerage account likely offers your quickest and least expensive path to buying stocks, funds and a variety of other investments. With a broker, you can open an individual retirement account, also known as an IRA — here are our top picks for IRA accounts — or you can open a taxable brokerage account if you’re already saving adequately for retirement elsewhere.
Dollar-cost average: This sounds complicated, but it’s not. Dollar-cost averaging means investing a set amount of money at regular intervals, such as once per week or month. That set amount buys more shares when the stock price goes down and fewer shares when it rises, but overall, it evens out the average price you pay. Some online brokerage firms let investors set up an automated investing schedule.