only a properly created cold storage or a trusted hardware wallet.
you can search for some hardware wallets if you are not tech savvy or don't want to bother learning how tos and if you are willing to pay. things such as Trezor or Ledger nano would work.
or you can learn more about cold storage and do it yourself easily. like creating a paper wallet with tools such as
https://github.com/pointbiz/bitaddress.org or make a Trezor like cold storage on your USB disk yourself
https://en.bitcoin.it/wiki/Cold_storageYes, I agree with you. Hardware wallet is more secure than the online wallet. You can download official Bitcoin wallet and other wallet and store Bitcoin on those wallets. Those wallets are very secure.