If it’s your first time playing Pokemon ever, then you’re gonna need to learn the fundamentals of the battle system before trying to learn about all the Nuzlocke tech. So:

• Type matchups are arguably the most important thing to learn in the whole franchise. Try to memorise which Pokémon are what type and what each type is weak/strong against.

• Bigger numbers are not always better. Pokemon can often have unique abilities or attacks that make them more valuable than they would seem based on their raw stats.

• Attacks that deal more damage are not always better than weaker attacks with higher accuracy/bonus effects.

And most importantly:

• You WILL get screwed by RNG. It’s simply the nature of probability that eventually, no matter how well you play, you have to constantly take risks to win, and those risks will eventually add up. As aggravating as it can be, don’t let it affect you too much and just keep playing. As long as you’re improving at the game, it’s always worth trying again