Here's two plants in the yard. First is low growing , maybe some kind of cypruss? Sorry for the quality of the second pic being out of focus, it might be too generic looking anyway for an ID now. Thanks.
Looks like a golden pfitzer juniper to me. Don't know about the sawtooth leaf edges but what can be seen of the bud of the seedling resembles that of an oak. What kind of oak is producing all the acorns? Probably those leaves rule that out but there may be another tree you know about nearby that could be connected with the seedling.
Hmm, I don't believe that's a seedling of an oak we have here (as it's mainly white oaks and some kind of pin oak). I'll look around tomarrow for similiar leaves.