You may want to speak to a professional accountant who knows about 501(c)(3) tax filing. Turbotax doesn't support it and I suspect the volunteers here don't know what needs to be reported. (I was treasurer of a church for many years, but churches are exempt from filing from 990, so I can't help you with the filing requirements).
You may want to start with form 990 and its instructions.
https://www.irs.gov/forms-pubs/about-form-990
The form does seem to want your income, even though it is not taxable. You also are required to report a great deal of other information about the organization. I recall that groups like Charity Navigator use public 990s to help rate the effectiveness of charities (salaries of executives, percent of income spent on program vs. fundraising, and so on) so there is probably a lot that the IRS requires.
There are also simplified versions called form 990-N and 990-EZ for smaller charities with much less complicated reporting requirements. So your filing requirements depend partly on the size of the organization.
Lastly, I will point you to the issue of Unrelated Business Income Tax (UBIT). Even though a charity may be generally tax exempt, if it generates income/profit from "unrelated business activities" that income may be taxable.
https://www.irs.gov/charities-non-profits/unrelated-business-income-tax
I think you may want to start with a solid education.
