I don't trade coins though but I assume its less risky to stick to the coins that are already on top and has been traded regularly.
The great thing with yobit is that you can get free new coins to test its waters.
I concur trading is very risky though very rewarding as well and i believe that it's very safe for you to invest into bitcoins or the popular cryptos by just buying and holding the coins in your wallet safely and securely.
So better start trading but before actually starting trading, you should have some good market knowledge and basic information about the technology you want to invest in. For example if you want to invest in Bitcoin and you do not know much about it, investment is vain. Also you should make your decisions about selling or buying keeping the market condition in the mind and only then you might be able to become a good trader.
Since the OP was obviously new In terms of trading, just like you mentioned he should know the basics knowledge about trading and to gain those knowledge, google Is his friend and watch some sample videos that might help for him to understand fast how to trade. And If there's someone trying to ask you or suggest those coin, you should decline because most of that scenario was a scam.