It’s important to do a little research before you start trading on any platform. Few things should be considered before trading on any platform, they are - check the reputation of an exchange, the exchange rate, trading fees, payment methods available on an exchange and the verification requirements.
Binance and Bitfinex are the top cryptocurrency exchanges where many users buy cryptocurrency.
Binance is one of the crypto exchanges with the highest trading volume and has more amount of coins available for purchase. It is based in Hong Kong, with offices located in several other countries such as Japan and China. It is available to all countries and US states.
BitFinex is one of the larger cryptocurrency in terms of volume and users. It is based in Hong Kong and has trading fees of .1% for makers, and .2% for takers. It is important to note that BitFinex does not allow US users to sign up for their exchange. Bitfinex is limited in the countries they serve and do not accept US signups.
Every exchange will have their own unique features and people choose to buy at the best exchange. They will select the exchange that gives the best rate. I would suggest to check out CoinSwitch for
crypto trading at best rates. It is an aggregator of many exchanges, it gives an option to compare the price of a coin across the exchanges and buy crypto at the best rate.