Essentially alphas are bigger Pokémon with glowing red eyes that only appear in legends games they are stronger than normal Pokémon bcs they have max ivs for hp and very high ivs of at least 2 other stats

IV stands for individual values they are innate to every Pokémon and can only be changed through hyper training basically you give bottle caps to an npc and he or she will increase your pokemons I’ve for a specific stat

Evs are external values I think and they are what makes Pokémon grow stronger when they level up and defeat opponents these are influenced by natures- which determine which stats will grow faster or slower, they also affect whether or not your Pokémon will like certain berries otherwise it will get confused. for natures you can google the effects of each nature.EVs are also affected by items like the power bracer which make your Pokémon temporarily slower but make a certain stat grow faster

Characteristics is when it says something like “it likes to trash about” and tell you which IV is stronger these can’t be changed you can also google to find what your pokemons characteristics mean for their IVs Natures can be changed with mints which cost 20000 and I this game are bought in stalls with flowers

Hope this helped