Hey! You should definitely take the time to make an account on bitshares, if you want you can use my link https://bitshares.org/wallet?r=trexicon8
Follow the instructions to create your account, and don't forget to write you username and password down and store it safely. A lot of people use password saving software because you are generated a long complex password to keep from getting hacked. No one can recover your account for you so you are responsible for the security of your password :)
As for Coinbase, its a good gateway to get some quick bitcoin from FIAT but its quite expensive. Bittrex is great for trading between cryptocurrencies but if you keep your bitshares on their exchange, you don't hold your private keys. If they shut down and take your crypto with them, you may never see them again!
Bitshares is decentralized so it has no central point to shutdown at a moments notice and you hold your own private keys. The current downfall with bitshares is that it doesn't have all the coin pairs like Bittrex does, but new pairs are being added as the months go on. Another plus is that trading on bitshares costs a fraction of what centralized exchanges cost.
Good luck in your trading!