Good luck! I'm doing it too right now on a scientist (he only fishes on his days off though). My biggest tip is find two cheap frogs and start breeding them right now for bait. I go with cheap to keep the household bills lower and you might need a bunch.. I'd go for at least a stack of 10. Also start a stack of medium fish... again I go for the cheapest I think that might be Bass or Trout .. it's been awhile and I'm not there yet on my sim. They can sit foul in your inventory.. I know that sounds gross but you'll need them for bait. At least they don't start stinking like bad food..
I just fish all over with plants that I collect in the area I'm fishing in until it's time to head to Sylvan Glade and Forgotten Grotto for the rare ones. Also that Red-Tailed Black Shark that you get in Oasis Springs Park.. I've only caught it from the two back fishing spots.