To verify the funds are *still in* your wallet and have not been spent you need to create a Cold Wallet with your mnemonic key (all your funds) on an airgapped computer with an up-to-date copy of the Monero Blockchain. When finished you will have to securely erase the wallet or connect it to the internet and it becomes a Hot Wallet.
Unzip and open the paper wallet generator (monero-wallet-generator.html) into a web browser on an air-gapped (@airgap) computer that hasn't been used before, or has had a clean installation of the operative system.
Whichever method you chose, be sure there's no copy of the Monero wallet left over on the device you used. You may need to securely delete the Monero wallet if you saved it to a disk, or make sure your printer does not save a copy in memory.
