Don't worry! It will get easier the more you practice and as you progress through the game. One of the biggest issues that new players face is the extremely difficult fishing minigame in Stardew Valley. How to fish and how to use bait in Stardew Valley
Regardless, here's everything you'll need to know to build up over the next couple of seasons or years.
There are a ton of options available to choose from, or you could do a bit of everything. Do you want to become a truffle oil tycoon, or do you want to start establishing a vineyard? Perhaps you want to grow a bunch of tea leaves or fruit trees. After you've nailed down the basics and established yourself and your farm, you'll most likely want to start building up your machinery, farm buildings, and even potentially deciding on a specialization.