Snotirl,
I'm glad you have gotten some African Clawed Frogs. These are the larger frogs that have individual pointy little fingers with NO webbing betweed them. (Their feet are webbed, of course.)
They are totally aquatic and will dry out if they are out of the water. I have also had them jump out of the tank so it is a good idea to prevent this by covering or blocking all the spaces at the top of your tank.
I would not call them aggressive and they will live in peace with other frogs and fish of a similar size. They are, however, voracious eaters and they have rather large mouths. DO NOT keep anything in the tank that will even remotely fit in them.
To illustrate this, I gave two of these frogs to a friends little boy. I also gave him an albino cory cat. They all lived happily in a 10 gal tank and grew to their full sizes. One day my friend was cleaning the tank and saw one of the frogs just gobble up the cory cat. She tried to save it but could not pull it out of the frog's mouth. She then called me up in tears. If she hadn't seen it happen I would have thought that perhaps the fish had died from other causes and been eaten afterward. (The frogs will eat dead fish.)
The good news is that they do well in a temperature range of between 60 and 80 degrees so you could keep them in a tank with your goldfish if you wanted to.
I had mine in with my goldfish but took them out after awhile because the goldfish were getting large and were getting most of the food.
I've had good luck feeding them a product called Repto Treat, blackworms, boiled shrimp, dried tubiflex worms, and feeder guppies.
Please do not take them out and handle them. They are delicate little creatures and can be hurt easily. But, if you happen to touch one under the water, you will find they are smooth as satin.
By the way, they can live for 20 years in the right conditions.