Little Help Here

I'm terrible at this. I need to pick one starter Pokémon (or "starter" like Eevee and Pikachu are) for a story. They have to be cuddly and protective - the character suffers depression and they're gonna need some love and support. Being able to speak isn't the point. If it comes down to it, sign language is a viable task for a Pokémon to learn if they have hands. If not, no matter. But, yes. Character in need of support. Which starter is best for this? I'm not talking about favorite, either. I'm talkative by about best for the task.

I would think that any of the "cuddly and cute" Pokemon would fit the role you're looking for. Eevee, Pikachu, Clefairy, Jigglypuff, Meowth, Minccino, Zigzagoon, Growlithe, and so on in that vein would be good choices. Just look through the list of Pokemon and see if any of them are cuddly and protective enough to be your character's support.

You could keep in mind the basic personalities that the Pokemon species have. For instance, with Minccino, they'd be more supportive by helping their trainer keep their area clean. Jigglypuff and Clefairy might help by singing lullabies so their trainer can fall asleep. Pikachu might not be the best for cuddling since it releases electricity.

So there really is no one Pokemon that is specifically an emotional support Pokemon. (Except maybe the Chansey line.) Any one of the smaller species that tend to have easy-going personalities would be fine.

Though I do like the idea of Growlithe being used, since you want a starter that's cuddly and protective. Growlithe are good dogs.

Far too many Pokémon fit the mold, even if you constrain down to starters and even if the character choice needs to have been properly trained to deal with depression.

I'm going to mildly lean towards choosing the Snivy line among the mainline starters. It is cuddly, green, peaceful, and unlike ahem other starters it doesn't evolve into the trite humanoid bipedal that is there to punch stuff. So more amicable even as it grows. Moreover they probably know to carry themselves with decorum even in bad situations as befits the royalty associated with them.

There's also Litten... I mean, it's a cat so that's about 85% of the work done, but the last evolution into a bipedal who has to go around punching stuff kinda ruins the momentum. And the whole "pretending to be evil" theme to Incineroar kinda sends mixed messages.

For non-standard Starters, Mareep. Fluffy, goes along with a calm pace, with a concept of herd and family and evolves into Ampharos who while bipedal is protective and doesn't go around aggressively punching stuff. Not with those arms.

EDIT: My consultants also say Cyndaquil. Nothing fluffier than a warm stoat.

I think Happiny or Audino would be the most helpful pokemon in this scenario, but maybe pokemon like Ralts and Lillipup could also be helpful. Especially ralts since it is the emotion pokemon and its evolution are very protective of its trainer.

Going by traditional starter pokemon, I'd suggest Chespin due to how it is capable of making use of sign language as a bipedal pokemon, and the protective, knight-like aspect it gets as it evolves.

Assuming we don't go that route... honestly, there's a lot of options you can pick from, like the aforementioned Ralts or Happiny. If you don't mind not evolving it, Riolu could also fit relatively well. We could also make claims for Espurr, Gothita, and if we really want to push the boundaries, maybe even Natu.