Thank you all for the advices!
I will buy today BTC and then start buying the altcoins I have chosen in Poloniex. Maybe they will stay there for a week or more, because I am not that into wallets and have to read more about them. As I said I prefer to have paper wallets as more secure.
glad to heard about this,, you do the right choice my friend, by choosing poloniex

just suggestion for you, try to learn about crypto trading,,
and you can make daily profit in BTC
regards