I have just tried installing Bitcoin Core recently as I was told its more secure than other online wallets, but i need some help regarding the following:-
- where to set the secret phrase 
- how to know my private key 
- My receiving address is it the same or does it change
- if my machine crashes how do i restore my funds (i know they are stored on the blockchain but how to have access to it with BTC Core??)
- what files do i need to backup and how to RESTORE it on a different PC or after PC reformat/crash ??...

thanks,