So one question too: for coins hold long term is recommended on like cryptopia, Binance and cex.io? Or where should keep it all together on which wallet?
I recommend to try ripple and litecoin. If you on cryptopia i will recommend Electroneum(ETN).
After you buy some coins, transfer or send it to offline wallet such as dekstop wallet or mobile wallet that have full control on your coin. It will give you options to backup your wallet using private key or something so it will more safe. Keeping on exchange wallet isnt really good but if you still use exchange then is up to you.