Making money on Amazon is a challenging task. If you have proper knowledge about the trends and product then go for it else without knowledge there is less than 2% chance of success.
You need to provide the customer with good quality of product so that your return ratio is below 5%. If you are able to maintain this ration throughout the year you can definitely get good out of it.
If you want knowledge then hire a Mentor for your business then start the business under his guidance. Chances of success will be more if you work under guidance.