How to sneak in a fish?

Yes I've try to convince my parents blah blah blah but I have a dog and guine pig and I didnt really take care of them went I was younger I've be trying but every time I do my mom says no no don't do that it's to mess or it's to hard and I really want something that's mine even if it's only a fish I have a spot where it won't be found I have money for everything I don't have a drivers liscense and my parents are over protective and I can't go to a friends house so I'm stuck once I get every thing I can get it in easily and the closest place I can get a fish is 6 miles away Ive done reasearch for nearing 1.5 months so anyway dont tell me I'm mean to fish I'm not I have everything plan out and I have 500$ ready to put toward the fish so how do I get a fish and supplies passed my parents