Since bitcoin price has raised very high now,you could even start trading with just 0.001 btc.Being a new trader,you should not invest huge money due to curiosity because you have more probability of losing it.Better start with small amount.Buy newer coins as their price would be much lower.After gaining experience,you would gain confidence to carry out bigger trades.In my experience,bittrex has more newly released coins.I started my first trade there.