If you want to be relatively certain no one is tampering with your wallet address, I'd suggest the following:

1. Fresh install of a some Linux distro
2. Fresh install of Bitcoin Core wallet (let it fully update/full node: https://bitcoin.org/en/full-node)
3. Once the wallet is good to go, power off the machine and remove it from your network

Plenty of up/down sides to all of the available cold-storage methods, but if you don't trust any third party solutions, the above is probably best for your peace of mind.

You can probably just generate an address once you've installed core, and write THAT address down on a piece of paper.

Just my 2 cents :/