Since i'm a new trader and i can relate to your experience, here's what i've learned so far:
1. Don't aim too high. If the profit is 5-10%, take it, don't expect it to raise much more. Of course the best thing is to sell at the top, but you will never know how high it can get.
2. Every other coin is related in some way to bitcoin. So learn to trade bitcoin first and learn how bitcoin prices affect other crypto currencies. From what i've noticed, if bitcoin prices go up, almost all other cryptos go up. The same thing applies when bitcoin prices go down.
3. Never ever buy other cryptos when you don't know too much about them.
4. Don't panic when prices go down, you can either identify  the coin that gets pumped up when bitcoin value goes down, or you can just hold.
5. If you are in a shitty situation like i was a couple of days ago with Bitcoin Cash, first wait, then react.
6. You can't win in all situations, sometimes you're going to lose, settle for the loss if the situation is very bad.
7. Learn about trading strategies, learn about indicators and so on.