install bitcoin core

This will encrypt the wallet and make it secure. It then may take some confirmation time to have it spendable. It is a wallet. Dat file to your USB sticks.

install bitcoin core

Keep the private key private! Sudo apt-get install bitcoin-qt. This article also represents no advice on investment or trading. After its done you will find your imported address in your address window. Very old computers can need several days or weeks. You still should backup your wallet.