If you want to be a good investor you need to be knowledgeable on whatever it is you want to invest in and you also have to have some startup capital.
Only a fool is going to invest without any proper knowledge on what he is investing. It's a must before you are going to invest, you should have enough background on what you are investing because your aim is to earn money not to donate money. And always get some help if you think that you can't your investment seriously.
A good investment must be identified before you put your money into it. It will be late if you put your money first and analyze it later. With studying and careful planning it will make your risk less compared to being unprepared on what you are investing. Also it is your money you should know the importance of it before spending it into something unknown. We all know that investing can be tricky but all we can do is study it so that we will know what can be the outcome for us.