Can you tell me why my refund is still in the pending status. I filed 3 days ago and still haven’t received an acknowledgement email. Is there anything I need to fix?

Pending simply means that your e-filed return is on its way and that the government hasn't accepted or rejected it yet.   There is nothing to fix, just have to wait for the IRS to accept or reject.

 https://ttlc.intuit.com/replies/6487426