To add a bit to @Vanessa A 's answer:
California can tax you as a non-resident on any income you have from work you actually (physically) perform within California. If you have such income, you report it by filing a non-resident California tax return.
Your resident state of New York can tax all your income, regardless of where you earn it. NY will give you an "other state credit" for the taxes you pay to a non-resident state, so as to avoid double taxation. You claim that credit on your NY tax return.
If you have income taxed by two states, then in TurboTax (with a couple of exceptions), you must complete the non-resident state return first, before you do the home state return, so that the program can calculate and apply the other-state credit.
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
