Welcome to Lioden!

I would highly recommend taking a look at the Lioden Wiki as it has a lot of helpful information that's segmented into different areas. I'll be linking to various areas on the Wiki here.

Here's the "Basics" of getting started. I honestly wish I had been referred to the Wiki a long time ago. I just kinda guessed as I went along. You can find the link on the top right by where your currency is.

I'm not too sure what rarities of things you're referring to... so I'll just cover the basics.
For Bases, Eyes, Manes, Markings and different colors, there's traits that are referred to as "Breed Only". These traits are pretty well sought-after. These traits can come from NCLs (Newly Claimed Lionesses that you find in Explore), the Weekly Raffle Lioness found here, or sometimes randomly through breeding, such as rosettes.
Mottled Rosette and Mottled Stripes are two markings that are only received through breeding a Hybrid such as Leopons or Tigons.

Other mutations vary in rarity. Lethals incredibly sought after as well, as people like to decorate them and freeze them since they're never supposed to live a full life.

Base Genetics
Combo Bases
Mane Genetics
Eye Genetics
Marking Tiers / Genetics
Skin Colors

Marking Slot Rarity Tables:
Raffle Marking Slots
Rosette, RMA Exclusive and NCL Markings

I would also highly recommend taking a look at the User Created Guides threads for information that the Wiki is missing.
Hope this helps!

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