3/ Never invest your all money in one coin you must diversity.
I totally agree with you, divide your capital. this strategy
could lessen your risks since you're hodling multiple
coins
This is financial management. If you dont have financial strategy and you are diving in this trading thing or any other crypto or business related thing, believe me you would be seeing such big losses. Every time when you intends to go for trading, better is to make some strategy. Devise this strategy in a way that your income must be divided and then you can go for different altcoins as well.