A cold wallet storage is the best way to keep your cryptocurrencies safe, the worst place to leave your cryptocurrencies are on an exchange as the coins are then technically in their possession. If the exchange goes under or is hacked then you can lose your crypto. There are decentralized P2P exchanges such as Plutus that are safe to use as the crypto is sent directly between users personal wallets, and Plutus enables integration of cold wallet storages.

Plutus are also a payments platform that lets you pay in crypto at over 40million+ stores which is pretty cool, should check em out https://t.me/plutus_group