Software wallets like Eletrum and myetherwallet(MEW)
Software wallet like electrum no be cold wallet, na online wallet wey e be. The only time wey your electrum fit be cold wallet na when you use am for airgapped device, and never connect the device to the internet again.
Personally I believe the best type of cold wallets that you would want to have are hardware wallets like the ledger because it basically has the highest security
E get hardware wallets wey better pass ledger, i no go even advise person make e buy ledger right now, because them dey lie to their customers, dey launched the ledger recover feature, when dem been initially talk say person seed phrase no fit leave the device, ledger is also closed source. If you wan buy hardware wallet, go for open source ones, and better if they are airgapped too.
I would advise the paper wallets it's basically free and secure to some extent just make sure your store the paper in a very secure place because if e lose your money don follow am lose
Paper wallet don dey outdated, it was a good cold storage in the past, but now that we have hardware wallets, no need to use paper wallets again, just go buy hardware wallet or create your own airgapped wallet with electrum.