The two types of brokers are full-service and discount brokers. Full-service brokers tailor recommendations and charge higher fees, service charges, and commissions. Once an account is set up, a discount broker can allow you to do it yourself at minimal cost through their website and offers support online, by phone, or in a branch when needed. The cost of buying continues to decrease with the introduction of apps. Apart from cost, a distinguishing factor is the research provided.
In addition to knowledge of basic trading procedures, day traders need to keep up on the latest stock market news and events that affect stocks—the Fed's interest rate plans, the economic outlook, etc. So do your homework. Make a wish list of stocks you'd like to trade and keep yourself informed about the selected companies and general markets. Scan business news and visit reliable financial websites. 
ECN/Level 2 quotes: ECNs, or electronic communication networks, are computer-based systems that display the best available bid and ask quotes from multiple market participants and then automatically match and execute orders. Level 2 is a subscription-based service that provides real-time access to the Nasdaq order book composed of price quotes from market makers registering every Nasdaq-listed and OTC Bulletin Board security. Together, they can give you a sense of orders being executed in real time.
In order to be successful at both stock trading and investing, you need to be patient and maintain your composure in every situation. The nature of work is stressful, almost hectic, and you are bound to be losing substantial amounts of money some days. It could be very tempting to try to recuperate your losses by “doubling up” on your gamble, or opening high-risk positions that were not a part of your game plan, but this is precisely what you should be avoiding. That does not mean you shouldn’t dynamically adjust your investment plan to fit the current market conditions—it just means you shouldn’t modify your plans in a rushed or disorganized manner while carrying an emotional burden.
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.