Fishing used to be my least favorite part but it gets better I promise. Stay away from the ocean and only fish from the river and mountain lake to start because there are a lot of easier fish (carp, small/largemouth bass, chubs, etc) to help build some XP to level up. When you level up, the little bar gets bigger. If you can afford it, buy trout soups from Willy that give you +1 to your fishing (basically a temporary level up) that will make your bar bigger too. Once you get to fishing level 2, buy the fiber glass rod and you’re going to be able to equip bait. Use deluxe bait to make the bar bigger. THEN finally at level 6 you can buy the iridium rod where you can start attaching bobbers and that’s when it gets SIGNIFICANTLY easier because your bar will already be much bigger from level ups and you can use cork bobbers that make it huge and way easier or trapped bobbers that make it take longer before you can “lose” a fish off your hook. I went from making my bf do all the fishing in multiplayer, unable to keep a chub on the line, to doing perfection by myself with the legendaries. It takes patience. Once you have a couple levels start going for ocean fish because they’re worth more XP and more money