I just started trading crypto currency. This is my first time to trade. What I did is just a self study. I read everything about crypto and trading and watch videos on youtube. Some did not makes sense

One question in my mind is , is it safe to just store my bitcoins and other coins that I bought on BITTREX? I have a blockchain account but the fee when sending and requesting withdrawal is quiet high. So I decided to just store it on bittrex. For the other crypto currency, I only have ETH Wallet.
Thanks for the help.
No, it is not safe to hold your money and use exchange as a wallet, although bittrex is big exchange and trusted one, but you never know what can happen.
If you want to keep your coins safe then keep them in your wallet and not some exchanges or other sites. You can ask the same question for gambling sites - is it safe to use them as a wallet? Answer is the same.