Perhaps consider an investment in a decent hardware wallet or signing device, like a Foundation Passport, a Jade, or a ColdCard.

Once you have the hardware wallet, you can use software, like Sparrow, to manage the process of stacking bitcoin, while securely storing the keys, used for spending, offline, on the hardware wallet.

You can connect Sparrow to your node to keep your queries to the blockchain private.

Once you've purchased from an exchange (like Coinbase or Swan), you can easily withdraw it by providing a cold storage address (given to you by Sparrow).

Since the keys are securely stored on the hardware wallet (with the seed backed up on paper or steel), all of the bitcoin you stack stay nice and frosty in cold storage.