One more thing...
Don't attempt the first grooming by yourself going off websites or videos. There's individual tweaks sometimes people do and not all dogs need the same type of grooming for show.
I semi agree with the others to be prepared for a long grooming session with a golden pro or breeder. It might not cost that much. With Bertie, the first couple years of showing - I always brought him to a mentor who did the grooming for me. I paid her $50-65. Which seems a lot, but it's a show groom.
I typically did the bath/blow dry at home + nails and brought my dog to her. The appointments usually were 2 hours, typically, with me standing there and assisting (holding my dog still).
That's trying to get everything done in one appointment from shaggy to show ready.
I typically do the grooming myself now and it does not take me that long - primarily because I don't do everything all at once.
My puppy is showing this coming weekend. I'm going to take a look at his nails, but I think they are too close to the quick for me to trim. So that will be it until Fri when I give him a full bath and blow dry. This takes about 45 minutes to an hour (counting the bath).
On Sat - I'll do a spritz/dry (or a bath at home and dry at the show). And I'll touch up on his ears and feet. I aim for an hour's worth of grooming directly before showing.
The more inexperienced you are - the LESS you want to do day of show. You don't want to use shears at all. And getting your dog wet relies on your confidence in getting him completely dry and coat lying the way it needs to be before showing. Keep in mind this is a breed that we do not like using hairspray. The coat has to be trained and maintained so it lies tight around the dog's body (like a jacket). Flippies and waves are fine, you just don't want the coat sticking straight out and exposing the undercoat.
You want a good pair of thinning shears. Primarily because they will go dull pretty quick with heavy use if cheap. So Kenchi or Geib are fine - Kenchi 5 Star is about $120. I love mine. Have not had to have them sharpened yet (I don't use them too heavily though).
Straight shears - you need a 7-8" pair. This is primarily for the ears. And you want a good pair because the sharper the better. And to keep them sharp, I'd just use on the ears. Dubl Duck Mercedes has a 7.5" pair for about $75.
Straight Shears (heavy duty use) - something cheap like Conair Pro. Yellow handle. These are $9 shears. They stay "sharp enough" for years. If you get a 6" pair, you can use these for cleaning up around the feet and under the feet.
Small Shears - Kenchi 5 star, curved works nice. These would be finishing shears around the feet.
Wire slicker - for the coat. And even with the bathing and blow drying. You want to do a nightly thing where you are simply brushing the coat the way it should flow. Down the back and down the sides, brushing the butt/leg/chess feathers down, etc. This will remove excess shedding between baths + help train the coat.
And again - you need a dryer and grooming table.
^^^^ That might sound like a lot, but believe me, it's a drop in the bucket compared to what other people spend on stuff. And they don't always have to.
All that stuff - it's stuff I would want to have even if I stopped showing my dogs. I would always want to groom them properly myself with the least amount of annoyance (dull shears chewing on the coat, etc).
And then all that stuff is for learning when you aren't showing. The first year or two of showing, it would be best to have somebody else grooming your dog for you. A golden exhibitor who grooms on the side (you'll get contacts from the club). It's less stress that way and less "fixing" for them.