Each floor has its own advantages, both are OK
Every exchange has its own advantages and disadvantages but all you need is to be active and monitor the market value so that you would be able to take decisions of buying and selling and in which coin you are finding the maximum possibilities of getting the most profit. Bittrexx and poloniex both are good but you can also try coinbase. Learn something how to trade and then enter into trading you will slowly slowly make your skills.
I think it iis goood to try it both first then in what exchangge do you feel you are safe and comfortable to trade then go to that exchange..
Just lie you both says they have its own advantage and disadvantages and for me in that i use to be flexible in any exchange where i have a good feeling to trade on.