The income is taxable in California, and Utah so I will give you some insight about how this works so that you can see you are NOT double taxed. Complete your Utah return first, then choose the credit for taxes paid to another state for the California income tax return.
Resident State: All income worldwide is required to be reported on your resident state return. Any money that is also taxed in a nonresident state is eligible for the "credit for taxes paid to another state" when you complete your resident state return. Your resident state does not want you to pay tax twice on the same income.
Nonresident State: Any money earned in a nonresident state is required to be reported on that state tax return. The nonresident state will tax any income earned from that state. Including income from property situated in that state such as rental income in your case.
You can try to use the instructions below to delete your California so that you can start over if you haven't registered or paid for your TurboTax yet.
https://ttlc.intuit.com/replies/3301384
