You were going to eat a tomato in which seeds were sprouting in situ? Sorry, but I shudder to think what it's condition was. Certainly long past the point of palatability.
But I digress. I'm going to take a guess on this, because I've never heard of anyone using chitted tomato seed. But if it's just starting to sprout, I would plant it, root end down, in seed-starting media. You can, btw, start a multitude of them in a 4" pot, rather than setting them individually in cells.
Other than that, Charron gave you the gist. Bump them at least once, after true leaves appear (true leaves will be the second set). Don't know where you are, but if last frost is sometime out, and the seedlings are getting away from you, bump them again, in a taller pot. Won't hurt anything, and, in fact, will build a stronger root structure.
However, before going through any of that, what was the source of the tomato? If store bought it was likely a hybrid, which means it will not breed true to type. You will get a cross-section reflecting the genetic make-up of the parents. Sometimes there are happy surprises from that. But most of the time the results are disappointing.