Welcome to Final Evolution, a Cobblemon modpack. The main focus of the pack is Cobblemon with a few other mods to add flavor. Below are the main mods and some of the changes included in them.

Cobblemon - This is the main point of the modpack. The basic ball recopies have been removed and shunted over to Immersive Engineering. You can still find balls as loot in chests but the point is to make them more rare and something that's worked for.
Berry Pouch - Adds a pouch to store all those Cobblemon berries in one place
Cobbleloots - Adds random loot ball spawns in the world, watch out for those Master Ball loot spawns as they can really propel you forward!
Battle Tower - Adds a battle tower mechanic to Cobblemon.
Fight or Flight - Makes the Cobblemon fight back if you attack them like a regular Minecraft mob.
Pokenav - Help find the Cobblemon that you're looking for.
Raid Dens - Adds raid dens to world generation
Mega Showdown - Adds the Mega mechanic in.
Cobbleworkers - Adds world interaction to certain passive abilities such as Pickup allowing for items to be "dug up" when that cobblemon is placed in a pasture block. Note that the balls have been removed from this loot table though.

Immersive Engineering - An oldie but a goodie plus with the integrations with Cobblemon this is how you'll craft most of the balls you'll need to catch 'em all.

Beyond these feature, and addon, mods there are some support mods.

Bad Mobs - Removes natural spawning except for bees, wandering trader, trader llamas, Wither, Warden, and Ender Dragon. This means no hostile mobs to worry about... unless you get near a spawner because spawners WILL still spawn mobs!
Easy Villagers - Just a mod I really like, totally optional for your use.
Integrated Dynamics - Again, a mod I like but can help with automation and decoration too.
Silent Gear/Gems/Productive Metalworks - For those "unbreakable" tools.
Mystical Agriculture - So you can automate resource production and focus on the cobblemon.
Sophisticated Backpacks/Storage/Functional Storage/Refined Storage - Inventory space and management is always an issue, and Cobblemon adds a lot more items.
Relics - Because they're fun.
Apotheosis - This is mainly added for the functionality added to the spawners. Given natural mob spawning is disabled this, combined with the Farming for Blockheads Market, allows you to obtain spawn eggs and thus spawn whatever you need to.
FramedBlocks/Rechiseled/Simply Light - For decoration because what good is having a massive base if you can't decorate it how you want?

Beyond that there is no quest book, check JEI, and have fun!

P.S. Icon was cropped from a "free for use" image. Original credit to geralt on pixaby for the image.