Everything depends on the market...
1.Nobody knows when it is the most profitable to buy cryptocurrency.
2.Reselling is more profitable but more risky

3. If you resell on the exchange, there are no difficulties. If somewhere else, you have to find your customer.
This is right, but topic author should educate himself more before entering market/trading.
Knowing this things its only begining, you should learn about keeping ur crypto safe also before you start and many many more. Postpone ur trading ambitions.