By all means stay away from bitconnect, that is just a scam coin, ponzi scheme.
About the real trading exchanges, when i started in crypto i joined bittrex. I have nothing bad to say about them, what i like about bittrex is the user friendly interface, very straightforward. The only thing bad about bittrex is that sometimes is slow ( not sure if ddos attacks or too many users online at the moment).
The second exchange i know is binance, i joined later after bittrex. Binance is also a good exchange, the basic exchange is simple and u also have a more advanced exchange where you can use indicators and stuff. The downside of binance is the fees, either you have their coin (bnb coin) to pay fees or you will be left with a fraction of the coin you bough, without being able to trade it back to bitcoin.
Goodluck! And remember to educate yourself before trading to avoid loss of money