In need of some help first timer

I am a first time grower verry low budget and I have a problem my plant is about a week or so old and it has 4 leaves 2 mor on the way but one of the leaves is starting to look like something is eating it I have two cats and I had it were they might have gotten it but im always in the room and I have never seen them go to it. It also looks like bug bites but I checked real close and there are no bugs what else could be wrong any clues?

You would probably need a microscope to see bugs. I got one at my local hydro store for under $20. For spider mites I would use neem oil because its cheap and effective from what I have read. Pictures would really help though.