As long as it is what's advertised, it should be fine.
It's intended to house marine fishes, so should be great for goldfish. With that filtration system - if you maintain it and do water changes, you could probably go with five fish in the tank. Though if you're starting with young fish I'd suggest adding no more than two at a time, then waiting about three weeks before getting another - that will set the filter up nicely with beneficial bacteria. If you're starting with larger fish, just one to start would be better
Though five adult goldfish would probably look rather crowded in there if you had any kind of decoration.