I think small amount around 0.01-0.05 btc is enough just to learn first how trading works. .because its too risky if you just a newbie and you don't know how to trade.. but after you learn and experience of loses in trading and you can now making a good profit with your own margin you can increase your investment to make more profit every time the price increased..
Thanks for your comment I really appreciate that but can you tell me a way where there would be no losses at all. Like if I buy something e.g BTC and then hold them as long as their price increases. Will that also be in loss? Is there anyway or platform where one can hold the money and wait for the right moment to sell that for profit?There're a way if you want to get profit all the time that's holding,yes holding a coin is the way for you to get profit without loses.if you're using small amount,try it in altcoin because when you get a profit you can double your money,there's many platform something like bittrex,poloniex,ccex and etc(this is for altcoin,you can hold bitcoin in there too.but they're focuse in altcoin)
If you only want to trade bitcoin you can go to bitstamp,kraken and etc.google it,many platform that you can use to hold or trade your money
