You will have to Upgrade your fishing pole to at least Gold to catch Large fish.
No you can only catch trash so don't bother
There isn't a where and when to fish to obtain a large fish as it depends on the level of your fishing rod, I forgot which ore you have to use to upgrade your rod before you can catch a medium or large fish though...
Early in the morning.
You have to have upgraded your fishing pole to at least gold. After that you should be able to catch all sizes of fish, you have to hold down Y to power it up first though.
Catching a large fish is random so is all the other fishes.
You have to fish. Eventually you will catch a boot.
When you catch a Fish you will be holding it in your hands after you pull in your line. So if you pull in your line and you are not holding a fish you didn't catch anything.
To catch a big fish I think you have to have a golden (or higher) fishing rod. The iron will catch you small fish...the silver will get you medium...so gold should get you big fish.
You can't buy them, you have to catch them with the fishing rod you get from Greg.
In Harvest Moon: Tree of Tranquility you can catch the Woodfish in any season. Just fish in the Harvest Goddess's pond between 7:00 pm and 5:00 am.
You can make:Grilled Fish(Medium fish in frying pan)Fish Stew(Medium or Large Fish in Pot)Fish Sticks (Medium or Large Fish in Mixer)Sashimi(Medium or Large Fish No Utensil)