How to take care of 4 fishes? Any Advice?

I bought 4 fishes yesterday and I think 2 are Goldfish (I think). My dad is going to buy me a aquarium soon so right now I'm keeping the fishes in a large Fish bowl. I have also decorated the Fish Bowl with Pebbles and other things. I'm worried that they will die soon. Any advice on how to keep my 4 fishes alive and healthy?