Best option for most people to hold Bitcoin long term is good open source hardware wallet, something like Passport and Jade are good because they are airgapped, but Bitbox and Trezor are also acceptable.
If you don't want to spend money on hardware wallets, you can always use your old smartphone (or laptop) and turn it into cold storage without internet/mobile connection.
Whatever wallet you use it is more important that you make sure seed words backup is offline written on paper or metal, and in safe place.