Buy a Rod at the bait shop next to Ferris wheel
Only Buy Worms and Curly Bait
Curly bait gets you rare items-Pirate gun, Sea Dollar, and mostly trash!!
Worms get you rare fish
Left click to cast and start reeling in fish once they bite and right click to turn screen
you can scare fish away by clicking once or moving your mouse around, this will only scare away the one fish thats locked on to you.

it doesnt matter where you fish, the fish will all be the same
you can only fish in the blue boxes and rings, kinda buggy and you may need to move around before you can cast
fish will pull back a little bit more right before they bite
you can press left ctrl to pull out right before you lose a fish to save the bait
Turning on Fishing Opeque Mode can help a ton

about 89 hours to catch 1 of every fish, screamy boi was the last one
4,505 fish caught
757 rare fish
about 57 hours to hit max xp, but its a little bit easier now. about 37-40 hours
cost me about 2,501,900 units in bait. some of it i purchased in shop and not on tower unite so i have no way of knowing how much it all costed. i should have kept better track of it and im not 100% sure thats right. still got a bunch of bait in my inventory that i never used when i found out you only needed curly and worms.