I love fishing... I go fishing every "day".
It's amazing how much time you can spend playing this game and accomplish so little. I love that, there's no rush. I ride around and explore, I hunt, fish, sight see... and then I'll go do a mission, maybe, maybe.
Head down to Saint Denis once you get to episode 4, it's very cool and there's new stuff to buy
No spoilers, but once you complete a certain mission...money is not an issue. If you are careful.