As simple as this question sounds, a new person trying to buy some bitcoins may encounter great difficulty in knowing the right channel to go through to acquire some bitcoins and as such, it would help that explanations and comments are as simple enough that anyone can understand.
Although am still a new potential in the cryptocurrency market, and newer here, i have done some digging in my offline research hours to know that the best way to buy some bitcoin is through an exchange. While there is the decentralized exchange, there's also the centralized exchange like Binance, Kraken among others of which one can download on an app store, register, fill in the kyc requirements and of course connect to your bank cards to do the transfer and get the exact amount you paid for in your wallet on the exchange or have it transferred to a cold wallet which is not a wallet provided by the exchange you bought the bitcoin from.
There is also the need to understand that the price of bitcoin fluctuates in the crypto market, and it is wise for one to buy more when the price is down and sell when the price is higher. If one should know how to follow security tips of account and wallet management, then they would have become successful at owning bitcoin as a crypto investment than someone who sort the help of a physical broker to do same and are exposed to as much higher risk than just scams and hacks but kidnapping and other cybercrimes that could befall any unknowing investor from breach of privacy of investment.