actually it is very easy to do the trade for cyptocurrency,
all that you need to do is buy and sell,before doing any trade you need to find your output and input.
you should find the place for you to deposit your cash/fiat/money and then convert it to cryptocurrency.
after that find the place for you to encash your cryptocurrency.
usually,the place for you to deposit your money is the place for you to encash your cryptocurrency.

the advantage doing a trade in cryptocurrency on exchanger is some of them does not require our document to do the trade,
and it's very easy to send your money/cryptos,and you can keep yourself in secret.

the disadvantage doing a trade in cryptocurrency on exchanger is a lot of phising attempt will happen when you try to do it,
and the most important thing is it's irreversible.
whenever you or not you send your cryptos to other wallet,you will never can reverse it back or forever move to that wallet.

arbitrage is not easy as you think,
you need a lot of money at least to do it,and momentum.
a lot of people doing an arbitrage but most of them did not get profit from it but instead loss.
because it's require a confirmation for every transaction and some of them will be delivered after a hour or more than that.
in cryptocurrency in the next 5 minutes the price can change higher or lower.