No investment is ever truly "safe".

As with any other investment there's always an inherent risk that makes the investment, well, an investment.
Now, having purchased BTC and trying to find the best way to store it from hackers is an easier feat. As stated above, there are numerous wallets both online and off, all of these have different advantages and you can choose the one that is right for your needs.

Keep the private keys away from any public sources and don't walk down any dark alleys and you should be able to remain safe. Also, try to always verify the sites you're using are 'secure', as phishing sites are probably your biggest threat.

Happy hodling!