Organization began using QBO on May 1, the beginning of the fiscal year. How do I add donors into QBO between January 1st & April 30 so CY statements are correct?

Let me help you add your donors and enter transactions for the first quarter, Curtis0401.

If you already updated your account for a nonprofit organization, just add your donor as a customer in QuickBooks Online (QBO).

Let me show you how:

1. Click Sales on the left side menu.
2. Tick the Donors tab.
3. Tap the New donor button.
4. Enter all the necessary donor details. 
5. Press Save.

To have your statements correct for January to April, we need to record all fund donations you receive from your donors for that period. Just follow the steps and details in this article: Track funds you receive from donors in QuickBooks Online. Then, proceed to Step 1 until Step 5 (except for Step 4: Add your donor as a customer section) to complete the process.

I've got a link here that provides you with articles about managing your customer/donor transactions: Sales and customers gather topics for all your company's income and customers. 

I'm just one post away if you need a hand with running your financial reports or any QBO related. I'll be here to ensure your success. Have a great day ahead.