The best you're gonna get are guesses.
Not possible to identify a strain by a leaf. If you don't know the genetics when you drop the bean, you'll never really know.
You can tell if it's predominantly Sativa or Indica, sometimes, by the leaf structure and growth traits. But with so many hybrids, and phenos out there that it's impossible to narrow down beyond that.
AND, you could always have a plant that grows like an Indica, but smokes like a Sativa, and vice versa.
Smoke test will be the determining factor if you wanna grow it again or not.
If it's healthy, clone it and keep it going, until you harvest the first one and determine if you like it.