I'm guessing this is when you took it to the Judge, who tells you about your Pokémons' IVs.
"Outstanding Potential" means that when you add up the total number of all IVs in every stat, you get 151-186IVs. This is really good! A Pokémon with outstanding potential has an average of 28 IVs per stat.
Here is a way to find if your espurr has perfect IVs.
If you keep listening and he says something like "can't be beat", that means your highest stat is perfect: 31IVs. And, if he tells you something like:
>"Incidentally, I would say the best potential lies in its HP."
"And its Attack stat is also good."
"I see, its Defense stat is also good."
"Its Sp.Atk stat is equally good."
"Its Sp. Def stat is good as well."
"Well, its Speed stat is also good."
That means all the stats are equal to the best stat, so if he says both, you got a perfect espurr!
Source + Own experience
Welp, my team building skills are rubbish and I'm no competitive battler, but I'll try to make a moveset for your espurr!
(Yay terrible movesets)
First, evolve it. Higher stats=Higher performance.
Your nature isn't too good, and most prefer male meowstic because of prankster ability but if you want to stick with this Pokémon, I'll try. There's always breeding though.
Meowstic @Light Clay
EVs: 252 Def/252 sp. Def/4 HP
This is a terrible support meowstic moveset.
Basically, it's there to set up screen for your team. It'll probably die quickly, but if you survive you can use heal bell to remove status or STAB psyshock to finish off opponents.
If any competitive players have something better, comment because I know this moveset won't work that well