In all reality by the time you get my message the kitten may be dead. My mother ran over a mother kitten last year and I took the three kittens to feed, as they need fed every three to four hours. It was definitely a full time job. I do actually have some kitten formula left if you live in the 76179 area.
But as far as caring for this kitten it is going to be difficult. Firt you have to get a kitten bottle. Secondly you have to force it to take the nipple and that is the hardest part. The kitten needs to drink at least one oz. every three hours or it will become dehydrated. This can actually happen very quickly. All three of the kittens I took lived UNTIL I started weening them to solid food. During that time I cut back on the formula feedings and suddenly I had my best eating kitten lethargic and non-responsive. By the time I took the kitten into the vet, it was too late and the kitten had to be put to sleep. I had been feeding these kittens for over 6 weeks and suddenly lost what I thought was the healthiest one!
It's very hard to keep them alive at this young age and it's not a job for a child. You will have to be committed to the feedings and you MUST make the kitten urinate and poo manually. There are plenty of websites to help in that area as well, as it's not an easy task at first.
I hope the kitten survives. I felt a great sense of accomplishment after saving even just the two kittens, but it was a ton of work.
Also, don't forget to keep the kitten warm with a heating pad. Stroke it often on the back of it's neck with a warm wet washcloth so simulate a mother cleaning her kitten.
I wish you the best of luck.