While I do think that Coinbase is a very safe online exchange, the best practice is to use a Hardware wallet for larger sums of Crypto.
When it comes to Hardware wallets there are several choices, however what are most commonly regarded as the top two are:
Ledger and
TrezorI've given you links to both of them, so I suggest you check them out. From personal experience, you cannot go wrong with either wallet, they're both great and as long as the end user remains vigilant they will help you keep your funds safe.
For maximum safety, make sure to buy them directly from the official sites not from third party sources such as ebay.