The Golden Trout is probably the rarely available fish in Animal Crossing; which is why its times during the availability in ACNH are incredibly specific. Golden Trouts are merely available between 4 pm to 9 am inside the months of March, April, May, September, October November. Since March is approaching, you ought to get yourself prepared ahead of time by knowing each of the locations of Golden Trouts and also the methods of catching them.
So, firstly, what you must know about Golden Trout locations is the fish could only be found inside the highest points of one's island. ACNH Buy Items in advance is a wise choice. This includes the biggest cliff-top pool which is along the waterfall and all of the cliff-top rivers. Catching the Golden Trout can be another bit tricky and needs great luck. First of all, you should craft a unique kind of fish bait. For this, you will need the squirting Manila Clams which can be dug on the beach.
You will then craft each clam to a single helping of fish bait. Sprinkling this bait into any body of water is likely to make the shadow of fish visible for your requirements. However, be sure you only sprinkle it up from the water bodies with the locations already stated. You also need to have your ladder along with you since you must climb to the very best points within your island first. Then chuck the ball fishing bait right into a suitable body of water and cast your line.
Besides, you need to prepare about 40-50 bait while going fishing. This is because the fish is fairly rare and may take you to purge to 50 baits prior to finally catch one. You will then either sell the Golden Trout with an amazing rate of 15,000 Bells to Timmy Tommy or bring it to Blathers being displayed for the museum.
Whatever you choose to do, just don't leave it within the Nook's Cranny DropBox as it will be sold for 12,000 Bells there.