I am trying to set up some sub accounts.
Hi there, @Neile.
I got you covered with setting up sub-accounts for your personal expenses in QuickBooks Desktop. Let's get this started.
To add sub account to you'll need to add a new account and set this as a sub-account to your desired account.
You may check out the screenshots below to guide you through the steps:
For more details about this procedure, you may refer to this link: Create, edit or delete account in QuickBooks.
Also, here's a great article that you can read through about the Chart of Account for your future reference.
There you have it, Neile.
Keep me posted how it goes. I'll be around to provide further assistance if you have any concerns. Enjoy your weekend!