There is some exchanges you can trade: Bitfinex, Bittrex, Poloniex.
Also there is Bitshares where is a decentralized exchange but the liquidity is not too much, but for small trades is ok.
I don't support any exchanges in particular, but I heard a lot of people talking that had problems with Poloniex, there is a lack of support in Poloniex.
Never put a large amount or 100% of your capital to trade in an exchange, keep in mind that when your money is in the exchange they have the control over your money.
Also I like to exchange in Shapeshift or Changelly.
My opinion, as I don't trade by margim, I prefer exchange to the currency I want and keep in my hard wallet, like now I exchanged some BTC for LTC, that's it.
Always put stops in your trades, even if you are exchanging like me, consider exchange back to the currency that is going better when drops to your stop loss line.
check this website for charts : www.tradingview.com or this one www.investing.com both are free
Good luck & Good trades