After doing that you should be able to dump the keys using dumpprivkey on the BGL Core console.
The file you store your private key should be encrypted. The same goes for your wallet.dat file. If hackers can get access to your private key, your coins will be stolen.
A very bad practice is keep your private key in Notepad file, unencrypted. You can use Keypass, read more in
[GUIDE] How to Create a Strong/Secure Password