Hello! First of all I want to warn you that trading Bitcoins is the highest risk when it comes to all Bitcoin or cryptocurrency activities. This is because Bitcoin prices is very very volatile. It changes every second and no government or central bank regulates it. So you will never know when a crash of price will happen  or if there is a bubble that will burst.

However, you can try to minimize the risk by doing proper analysis. You can use both technical and fundamental analysis and combine it to come up with a good decision of when to buy and when to sell.