I usually don't bother to login to comment, but I felt compelled in this case. The other replies include a lot of bad advice. You sound like you don't have much of experience actually using bitcoin (or cryptocurrencies). So the best (most secure and easiest) solution is to buy a hardware wallet and use the wallet app which they provide. I suggest either Trezor [1] or Ledger [2]. Do not buy a hardware wallet from secondary marketplaces or second-hand resale websites - buy direct from the developer's website only.
[1] https://shop.trezor.io/
[2] https://www.ledger.com/
For added opsec:
- Use a temporary email address on the order form (e.g. mailinator or similar).
- Do not ship the goods to your home address. Pick-up your order in-person at a drop-off spot, post-office, or have it delivered to your workplace.
A bit more information about hardware vs. software/app wallet:
- Hardware wallets protect your bitcoin and cryptocurrencies by keeping your private keys secure on a dedicated USB (or air-gapped) device. The private keys never leave the device.
- If you use an app on your phone or desktop computer, your private keys could be stolen by malware. This is the exact attack vector that hardware wallets are designed to protect against.
Good luck!
[1] https://shop.trezor.io/
[2] https://www.ledger.com/
For added opsec:
- Use a temporary email address on the order form (e.g. mailinator or similar).
- Do not ship the goods to your home address. Pick-up your order in-person at a drop-off spot, post-office, or have it delivered to your workplace.
A bit more information about hardware vs. software/app wallet:
- Hardware wallets protect your bitcoin and cryptocurrencies by keeping your private keys secure on a dedicated USB (or air-gapped) device. The private keys never leave the device.
- If you use an app on your phone or desktop computer, your private keys could be stolen by malware. This is the exact attack vector that hardware wallets are designed to protect against.
Good luck!