When you receive your first payment is not really factor.
What you need to consider is what your total taxes will be for 2019. This will include income tax AND self-employment tax. The SE tax is something you haven't had to deal with before. It is roughly just under 15% of your net income from self-employment.
Hi:
What you need to do is consider your total tax on what I presume will be a return of married filing jointly.
You need to estimate your total income tax plus SE (self-employment) tax. From that, you would subtract any withholding, less any credits, pre-payment credits, etc. Then you would spread out the remaining tax over the estimated payments. It might be easier to include some payment in the June filing, that way the remainder of the payments won't have to be as large. The SE tax will greatly increase your tax bill.
See the following link for some more information. The link also has sub-links for forms and further information
https://www.irs.gov/businesses/small-businesses-self-employed/estimated-taxes
**Disclaimer: Effort has been made to offer correct information; but due to the discussion forum limitations, the poster disclaims any legal responsibility for the accuracy of the poster's response**
