I'm new in cryptocurrency.

Have been lurking this forum for last week and also did my first investments.

I have invested in:

GNT
GAME
STRAT
TRST
SC
WAVE

I bought them at Poloniex and Bittrex. Is it safe for now to store them there?
Or should I store them in separate wallets? I'm new, so It would be harder for me as I have to create a new wallet for each currency. Or is there any other safe alternative that can store everything? I have heard of Jaxx.

Also, you can discuss or suggest me about my invested altcoins. Do you think they are good? I have profited from all of them for now except for GAME cause I bought it right at the highest bump for about 3$ and then the big crash/dump happened when everything hit red. I, of course, didn't know about that would happen cause I started to read about crypto on that day, lol.

Any tips are welcomed