Goldfish need room lots of room !
The oldest fish i had was a goldfish (a feeder) it lived for 15 years untill my wife sprayed the tank with air freshener:|
Breeding is not hard just build a pond in your back yard add fish, food, and
a large helping of time (untill they mature) the fish will do the rest!
in tanks remember the old rule one inch of fish not including the tail
to every square foot of surface area