That you are probably not going to become a millionaire as shown by many. You will meet a lot of fraudsters. You will constantly undergo FOMO and feel FUD. You will find it difficult to get genuine unbiased opinion.
You also need to build your portfolio based on your sound understanding of the cryptos you want to buy. You should figure out a way to store your coins in a wallet where you hold the private keys .
You will also need to compare the prices of various cryptocurrency across multiple exchanges. You can use CoinSwitch which is one of the
best crypto trading platform to compare and exchange over 300+ coins at best rates.