Cherrim is like, the worst nightmare when it comes to catch rates in GO. You literally have to have a crap ton of Ultra Balls and Gold Razz Berries just to even have a chance to catch it.
I've seen both forms of Cherrim a couple of times, but oddly I have yet to find Cherubi anywhere.
I've been playing the game for just over a week now, I'm almost at level 24 and my Pokedex is at 165 Pokemon. A few things of note:
> My main focus right now is the Mythical Encounter quest where you can catch Mew. I'm up to step 5 of 8, so half way there, but one of the requirements for step 5 is to catch a Ditto, which I've seen none of so far (are they rare, or am I just unlucky?)
> I'm hesitent to tackle any Raids higher than one star, because most of the time with Raids there aren't enough players around so I have to tackle them solo, which doesn't usually go well. I've had more luck in Gyms, so I do a lot of those.
> A Gift that I received from another player contained a 7KM egg, the ones that hatch into regional variants, and it hatched into a Galar Zigzagoon today. There are no Zigzagoons in my area, so I might have it as my Buddy for a while, because it's only seven Candies away from being able to evolve into Linoone.
> I remember reading that Seviper only spawns in the Americas and Africa, but they're a common sight where I am, in England.
> The group of high CP Pokemon I use the most for Gyms and Raids are Aggron, Pyroar, Swellow, Cherrim, Hitmonchan, Hariyama, Electabuzz and Magmar. I also want a strong Water-type, I'm on the lookout for Totodiles, Froakies, Claunchers and Skrelps to farm Candy. I'm also hoping to get a Sinnoh Stone soon so I can evolve Electabuzz or Magmar.
> I've been enjoying this new Sustainability event, most of the special research earns you Pokemon encounters, and these encounters have included lots of Pokemon I've never seen in the game before, like Oddish, Bellsprout and Goldeen.
> I still haven't encountered Team Go Rocket or any Shadow Pokemon yet, which does annoy me because a lot of the special research tasks I have include battling the Team Rocket Grunts.