I always read about public keys,private keys and speedphrases that you need to store them in a paper wallet or hardware wallet. The only thing I ever stored are the passphrases (those 12 or 24 words) I get from metamask or other wallet provider in the beginning of creating a wallet. Is this enough when I write them down and secure them?
Assuming the see phrase is created secure, and stored 100% offline 100% off the time, it’s perfectly safe to store your ETH.
For NFT’s and tokens it’s also important to only interact with trusted contracts, but since you’re creating a cold wallet there wouldn’t be any interaction with contracts anyway.
But to create a paper wallet I need to set up a new wallet on metamask. That means the wallet will be connected to the internet at least once. Am I right?
That would work, but it’s not really a cold and secure wallet then.
To be 100% secure you need to create the seed phrase offline. You can do that using a hardware wallet, or a wallet installed on a PC that’s never connected to the internet for example.
There are solutions available, but I can’t recommend any since I don’t have recent experience with this.
It doesn’t have to be a PC that has never connected to the internet. You can disconnect the internet connection, or use a VPN, etc