This is not an advertisement but a fair warning being I just went through a mess because of this.  Anytime you get an email from PayPal do not log in through the link in the email, this may be a scam.  If you login through the email the scammer will get your email and password and start charging away at your account.

Once you get to the point where you have everything taken care of order the security key from PayPal it is only $5 and this will make it impossible for anyone to hack into your accout. 

You may receive an email after this saying that your bank account or credit card rejected your transaction and they give you a case number, again log in through the address bar to check it out.

Great luck, I hope you all have a safe online experience!