what to buy
Bitcoin.
what not to buy
Bunch of shitcoins.
when to sale or not etc
Sell when you profit - buy low and sell high.
and i also have heard of people talking about getting in on the crypto for free.
How?
How to earn BitcoinsDon't get too over hype much with those news that are coming out whether they are good or not still your own intuition must be followed by doing your own research.
Popular Advice: Invest only what you can afford to lose.