>>57969260 (OP)>Playing a difficulty romhack as your second Pokemon experience after decadesLmao. Pokemon is a knowledge game first and foremost, if you don't understand the type chart matchups that might complicate things for you if you intend on building a team with good synergy that covers each others weakness. If you're playing a difficulty mod it would also serve you well to know which mons are "shitmons" based off low BST's (Base Stat Totals), abilities, movepools, and typings, not a total gamechanger if you use them depending on the hack, but knowing what to avoid will make your life much easier.
Pokemon get a 50% boost to moves of their type so those are your bread and butter, then you can worry about coverage moves (again, understanding type matchups is important), set-up moves (moves that boost your stats), and support moves. You need to be checking your mons stats to make sure you're not using physical attacks on a Pokemon with disproportionately high Special Attack, and vise-versa.
Bottle Caps can be used to max out your Pokemons "IV" stat values in the ice town, if you have any. Think of it like uncapping your Pokemons genetic limiters to achieve their full base potential.
Post your current team and where you're at in the game and we can give more direct advice. Make sure to include all relevant summary screens, showing stuff like moves, abilities, natures, items...
SV has the most QoL and freedom to change Pokemon attributes to date, so there's a lot of room to augment your team members.