Helpful information here about security with cryptocurrencies.
http://avc.com/2017/06/getting-hacked-lessons-learned/
One thing is that if you are in this for the gamble speculation, then you will likely continually be at risk as the easiest way to have funds available is to have them on exchanges.
Coinbase is known as being one of the "safest" but it is also vulnerable (see Cody's story). But following the rules of the above post will keep you "safer"
The other major problem with Coinbase is that it is limited to 3 coins (BTC, ETH, and LTC) at the moment. I use Poloniex and Kraken to trade other coins.
Where can i purchase Bitcoin other than coinbase? Thanks!