2. Open electrum
3. Import the private key: click wallet -> private keys -> import. If it is qr code, click qr code icon next to the import button.
Scan QR code is only possible if you use Electrum mobile, and with Electrum for desktop, you can not scan QR code.
Mobile devices are suitable for hot wallets and with small funds. If you want to store big fund, at least big fund with you, you have to use a computer, laptop that is safer than a mobile device. Best if you can have an airgap computer or laptop for your Electrum wallet.