That sounds like EXACTLY the place I need to be 😂 Perpetual Pleb right here.

If you want, get an old android device. reset to defaults. do upgrades. install blue wallet. Then DELETE all wifi connections. Device should remain offline now.

Create a new wallet and Seed. Store seed securely offline. Export the xpub to another phone(bluewallet) or laptop (Sparrow wallet). Deposit sats to new addresses. Delete wallet (even default old phone again if you want). You can now anly deposit to address. To spend you would need to import seed to old phone again, or a hardware wallet..

There are a lot of options, this can make things more confusing, granted...