Ethereum is an open-source, public, blockchain-based distributed computing platform featuring smart contract functionality. It provides a decentralized Turing-complete virtual machine, the Ethereum Virtual Machine, which can execute scripts using an international network of public nodes.
Create the wallet, download and store offline on a USB.
You can use this service to generate a strong password: http://passwordsgenerator.net
Link: https://www.myetherwallet.com/#generate-wallet
Related: https://www.citylogic.tech/what-the-hey-is-blockchain