Unless the tank was one third to half full of water ,and filter material was floating or submerged in that water ,and or fish were included with the purchase, I would be suspect of the tank being safe for fish. the tank may have housed one fish or a dozen or more. Were the fish healthy? how much time elapsed after fish were removed from the tank and you purchased it ?
As for what fish to place in the tank assuming, (always a bad thing) that the tank is indeed safe for fish, I would suggest that a trip to the fish store with pen and paper in hand would be a good place to start. Write down the names of fish that interest you and then google information on them or return here and folks will be able to help you with what fish would work together.