If you want to buy Bitcoin then only use localbitcoins.com
If you want to sell Bitcoin for fiat currency then only use localbitcoins.com
LocalBitcoins has no middle man, very safe to trade and you can pay below market price in some cases.
There is also the opportunity to make some money by offering to buy small amounts of Bitcoin for a low price because scammers and criminals like to sell their Satoshis as quick as possible without caring about the price too much.
Coinbase and Binance and all other exchanges have super high fees and most of the time you will be forced to pay market price or higher. Also the security of Binance has been questionable the last few years.
Be cautious of "Decentralized Exchanges" as most of the time they are NOT decentralized.
If you need a wallet to store Bitcoin or any other cryptocurrency, you should always have the coins stored on your local machine with no internet connection and have the wallet encrypted, even better use a hardware wallet that you can remove from your computer and store somewhere safe.
Never keep coins on an exchange.