I don't know just how small the habitat is, but you should probably get the tank set up as soon as possible. If the tadpole does not have any front legs yet, it doesn't need any land. 6-8 inches of water with some pebbles, maybe a branch sticking out and pond plants like water lettuce, duckweed, pothos would do fine. Tadpoles really appreciate a few hiding areas.

If you use tap water, please remember to dechlorinate it with a water conditioner. For food, algae wafers, tropical fish food and lettuce are good choices. A varied diet is always preferred.

When it develops front legs, that's when you should think about adding land elements using gravel, slabs of rock, etc. You can lower the water level to about 3-4 inches. Make sure it has easy access out of the water with ramps and slopes and such. When its tail begins to shrink, it will stop feeding until it's almost gone. That's when you should ready live food items like fruit flies, phoenix worms, 1/8" crickets.

Finally, I'm of the opinion that unless you commit to caring for the frog over its entire life, you should let them go while they're still froglets so that they get a chance to hone their hunting skills. That's assuming of course that you live in an area where they are native. If you do decide to raise a leopard frog to adulthood, keep in mind that they will eventually outgrow a 10 gallon. It can certainly survive in one, but that's akin to confining a human to a studio apartment.