I highly recommend you understand what an airgap is: https://cdn.discordapp.com/attachments/796935699034144798/1176597349301235732/image.png?ex=6578ad2c&is=6566382c&hm=8ed92ec3e72b8e1cbcf46596bbb50bff685a6c9d1decd67357278888ab81d5fe&

Good tutorial https://www.youtube.com/watch?v=-tLoiLo5fT8&t=115s

A gotcha with airgaps is bad entropy (see milk sad). So here's how you can create a seed phrase by hand using casino dice: https://armantheparman.com/dicev1/

For even more security considerations see glacier protocol: https://glacierprotocol.org/