To fish, u need : - Fishing Rod (or) Fisherman's Rod - Worms - Fishing Skill
Then, find a fishing locations. To recognize a fishing location, just look for fish jumping out of the water as shown in the pic.
Fishing locations are as follow.
North of Naos Sea Slug Abalone
North of Almasha Crucian Carp
North West of Kashgar Crucian Carp Catfish
North of Opet Catfish Carp
South of Brashkent Sea Slug Octopus Prawn
Far West of Vior Abalone Octopus Prawn.
Between Svaha & Turphania Abalone Octopus Prawn
North of Talasha Prawn
South of Tianshui Catfish Carp Eel
West of Amenta Mackerel
Don't forget to click "Auto fishing" so it won't stop fishing after getting one fish.
Fishing Skill level needed to get 100% Fish // Skill Level Needed
Sea Slug // 15 Abalone // 17 Crucian Carp // 21 Catfish // 23 Carp // 25 Octopus // 27 Prawn // 29 Eel // 31 Mackerel // 34
Notes: Unlike mining and farming, u don't need food for fishing.