Yes, it's possible to manage your transactions, @Ashley - FT. I'm here to provide some insights and guide you through.
Transactions will be posted to the associated account. Make sure you choose the correct account from the category drop-down if you want them to post under the subaccounts or any particular accounts. Please refer to the image below for guidance:
Once you're all set, browse this article to know how you can resolve the difference in your account balances: Reconcile an account in QuickBooks Online
You can always comment back if you need more help with this or QuickBooks in general. The Community is available 24/7. Have a good one and stay safe!