You can try decentralized exchanges or verified yourself in exchanges that provide fiat trading if you're not a pro yet because you may win and you may lose a lot on impulses either it BTC or USDT they both volatile. USDT does not have that much volatility but still fiat is more steady. I prefer Bitstamp though verification might take long time or just yse DEX exchanges EtherDelta or an upcoming DexAge platform would be nice choice.