I'm keeping some on bread wallet and copay on my iPhone. Going to get a trezor. Anyone have experience with these wallets? My exchange is Coinbase but everyone is saying don't leave it there. Question- when you remove your coin from the exchange into say bread wallet, does your private keys come too? Still learning about this. So I copy an address in "receive " in my wallet and paste it in Coinbase 'send'. Then I receive bitc. Is that my private key or if not, how do I get it? Thanks.
Before buying any Bitcoin everyone should learn the basics of dual-key cryptography and try to get a basic understanding of how Bitcoin works.
Each key, both the public and the private is a string of upper and lower case alphanumeric characters. When a new address is created, both keys are created together.
If you use an online wallet or keep your coins at an exchange, you're basically lending them to the exchange or wallet operators, the same as you're lending your money to a bank by depositing it into an account or putting gold bullion in a safe-deposit box. You have no control.
The exchange or wallet operators retain the private keys. If you withdraw coins from an exchange to an online wallet, it's the same as transferring money from one bank to another. You still don't possess the keys (or cash).
Hardware wallets like the Trezor are convenient but you still don't get to see your private keys. They are hidden within the device itself and you still have to trust the device's manufacturer.
The only way to truly own your coins is to generate your own addresses, either with a paper wallet generator or by running the Bitcoin program. Unfortunately operating Bitcoin a node entails accessing the internet and therefore makes you susceptible to hackers or malware.
This is why I choose to use paper wallets as described in my post above.