There are some good rules for this.
If you want to invest in this, then invest in Bitcoin. Never invest in more than 2 alt coins.

Do not invest more than 0.5% of your earnings. Better, if you are new, do not invest your hard earned money in something that you do not know. It is risky, it is like gambling lottery or roulette.

If you have decided to do this, read some books (stock market, forex, etc).  Then try to trade for 15 years on virtual money not on real money. Read everything you can on this, read everything you find on the internet, etc.

After 15 years doing this (on virtual money) you will learn that you can earn good money.