Quite honestly Priya I find frogs and toads from temperate regions of the world can be harder to look after than tropical species.

If you can ask the dealer to find out if they are captive bred or wild caught. I imagine they are WC in which case ask for the country of origin and thenm look up a temperature chart on google. If they are wild caught they could already have entered a period of dormancy before you got them. In the mean time I wouldn't bother with any additional heating for them...and to be honest you could probably just have the tank in a light room (not in direct sunlight)!

I'm not entirely sure why he's sold you these as a frog you can see. During spring/summer on a night then maybe!

For future ref I highly recommend Dwarf clawed frogs as a starter species - they are fully aquatic, cheap and can be trained take frozen food + they are usually fairly visible!

I'd like to know how you get on!