1. I buy Bitcoin using the PC Coinbase platform.
2. It goes up and I want to get out of the trade to make a profit.
3. The trade is still open.
4. I open the trade and the only option is "Cancel."
5. I click "Cancel" and the order is canceled.
6. I don't make or lose any money.
How Do I Get Out Of The Trade Without Canceling It?
Thank you for taking the time to read my post and replying.

Look at your account's dashboard and see how much you've got there and look at the history of your trades if you're able to cancel it as what you've said.
Then, when you see those amounts that you've got as your balance in your account and you already want to get out then the last thing you'll have to do is withdraw it. If ever you still got funds there on your Coinbase account.
And before committing your next trade, study first the platform itself so that you're aware of those buttons and what you'll do whether you'll proceed or cancel a trade.