Hi @michelle135,
The option to track income and expenses for two business entities in a single QuickBooks Self-Employed (QBSE) company is unavailable.
It's the same situation with QuickBooks Online. A single subscription is for a single company. You'll have to subscribe to another QBSE company for you to track the transactions of your other self-employed business separately.
With that said, I suggest you take a look at this article: Export your data from QuickBooks Self-Employed. It lists the steps on how you can export transactions, miles, and taxes.
Feel free to use the comments section below if you have other questions. I'll take care of them as soon as I can.