First, create an account on Coinbase.com by providing your personal information and verifying your email address.

Once your account is set up, navigate to the "Buy/Sell" page and select "Bitcoin" as the cryptocurrency you wish to purchase.

Enter the amount of money you wish to spend on Bitcoin and select your payment method. Coinbase accepts bank transfers, credit/debit card payments, and PayPal.

Review the details of your purchase and make sure everything is correct before confirming the transaction.

Wait for the transaction to be processed, which can take anywhere from a few minutes to a few days depending on the payment method you chose.

Once the transaction is complete, your Bitcoin will be added to your Coinbase wallet.

You can now view your Bitcoin balance in your Coinbase wallet or send it to another wallet address.

Keep in mind that Coinbase has a daily purchasing limit of $25,000, so if you wish to purchase more, you will need to complete additional transactions.

Keep an eye on the cryptocurrency market and consider buying more Bitcoin when the price is low.

If you wish to sell your Bitcoin, you can do so by navigating to the "Buy/Sell" page and selecting "Sell."

Enter the amount of Bitcoin you wish to sell and select your payment method.

Review the details of your sale and confirm the transaction.

Wait for the transaction to be processed, which can take up to a few days.

Once the transaction is complete, the money will be added to your Coinbase account and can be withdrawn to your bank account.

Remember to keep an eye on the cryptocurrency market and sell your Bitcoin when the price is high.