hi @Bluebeeee, I've had show and working retrievers (Flatcoated and Golden) My current Golden girl is from full working stock, I was on a waiting list for a year to get her, and the breeder only let me have her because I said I wanted a dog that I could do obedience with. All of her siblings are working retrievers. Getting a well-bred working dog is, in my experience, harder than getting a show-bred one.
They look very different, most of the show-bred ones are thicker set and paler in colour, with more luxurious coats. They should have a level "top line" along the tail and back.
My girl is only 24Kg, slim, dark, easy to manage coat (not very practical for working dogs to have coats that need a lot of care) She's very keen to DO things, retrieve, play hide and seek. Before lockdown we reached the advanced obedience class and her scent work was brilliant (picking out the hanky I'd held from a whole load on the floor), we'd started on Agility - she's a total delight for me to live with - not that keen on children, but she's not had a lot of contact with them.
Working line GRs can also be kennel club registered, full KC papers etc - and so can be shown, but they are not bred to conform to the physical beauty standards that show judges are looking for. Bigger shows might have gamekeepers classes where working dogs are shown.
Remember dogs are individuals too - their breed characteristics and parentage affects who they are, but so does their upbringing and early experiences. So you have to get everything right.
Any breed that becomes popular, like Goldens, will end up being bred, by some, for profit with no regard for health or temperament - show as well as "working" (and you get a fair few fake "working" breeders ) so you really need to find a breeder you trust, whose dogs you like, who are friendly and approachable, health tested with good scores etc. Be prepared to wait for the right dog.