You need to explore the sites with the greatest liquidity, pay attention to the daily turnover of these sites. It is also important to understand that there was a possibility to open short positions
For me the benchmark of the exchange is Okex
I trade there, plus access to futures, shoulders, this is a powerful tool if you know how to use it
But it's not enough to choose a site, you have to understand how to trade, what and when, so do not take intoxication into the market without a clear trading strategy,
information about patterns and ideas you can search on the sites of traders
here's a good one: http://www.insiderport.com/ 
Or find something that you like