Keeping Cod and other fish like Goldfish?

yes and no. you need to get a big tank 2 to 3 meters possibly and some types of cod/salmon live in warmer waters so you will need to buy a tropical fish tank suitable for them and i know there are websites for stuff like that. but in answer to your question no, unless you want to spend loads on equipment. but you can get some stuff cheap like on eBay. they sell everything!