It depends on what was sown. A lot of species need light to germinate, so the seeds could be OK if you remove the mulch. But, how will you know exactly where the seeds are??? Others may have begun to germinate under there, and then died because they couldn't break through to the light.

Given the circumstances, overall, I say you're probably better off chalking this one up to experience and starting fresh.

Definitely replant. You could wait forever. How did it turn out? Have you considered pre-sprouting? Soak them overnight, place them on a paper towel that's wet but not dripping, fold it up, and put it in a plastic baggy. Check it at least twice a day after 24 hours. (This adds air.) It must stay damp. I put it somewhere warm, in most cases. It depends on the seed variety.

When you see that a root is beginning to protrude, plant in well-prepared ground, or in 6-packs. It works for me. Good luck!

And being a newbie is great. You'll have tons of fun learning and researching. These mistakes are one we all made, so don't feel badly. :D