I have a verification of non-filing for 2018 on my transcripts but my return was accepted may 21, 2019. What does that mean?

Verify the status of the e-filed tax return using this TurboTax website - https://turbotax.intuit.com/tax-tools/efile-status-lookup/

Did you have a tax refund on the federal tax return?

If accepted by the IRS use the federal tax refund website to check the refund status - https://www.irs.gov/refunds

What is the status of the tax return/tax refund?