To get this achievement you simply need to adopt your first dog!
Any dog works.

Note: To my knowledge none of your choices on the dates matter, you simply need to go on them.

Attain the Unattainable [Anders' Route]
First, hang out with Anders twice. Then, attend Anders first date, hang out with him once again, attend the second date. Choose to hang out with Anders during the Dogwood Gardens event then go on his third date.

Datin' and Skatin' [Astrid's Route]
Hang out with Astrid twice to unlock the first date with her, after the date hang out with her again to unlock the second date. At the Dogwood Gardens event choose to spend the night with Astrid to unlock her third date.

True Crime, True Love [Felix's Route]
Hang out with Felix twice, go on the first date, hang out with him again, then go on the second date, all before the Dogwood Gardens event. Choose to hang out with Felix during the Dogwood Gardens event, then go on the third date.

Powerwalking on Sunshine [Maribel's Route]
Socialize with Maribel twice, go on two dates with Maribel, hanging out with her once between the two dates. Choose to hang out with Maribel during the Dogwood Gardens event and go on the last date with Maribel after the event.

Lrn2date [Robin's Route]
Talk with Robin twice, go on her first date, talk with her again, then go on her second date. Choose to hang out with Robin during the Dogwood Gardens event. After Dogwood Gardens go on Robin's third date.

Pillowfort for Two [Sacha's Route]
Hang out with Sacha twice then attend his first date. Hang out with him again to unlock his second date. During the Dogwood Gardens group event choose to hang out with Sacha. Go on Sacha's third date afterwords.

Rainbow Bae
Complete every characters romantic route.

Is it a Dog? Is it a Plane?
To attain this achievement you need level 10 fitness stat by the end of the game. Choose Cardigan as your dog for this one, as they have the highest starting fitness. Attend all Pawsonal Time for the fitness stat, these are often the only things that will get you past level 9. Training activities that increase fitness most are: Who Frisbees, Wins, Puppy Paddle, Jog with Dog, and Sprinkler Party.

The Politest Pup in Rainbow Bay
To attain this achievement you need your pups manners to be at level 10 by the end of the 15 weeks. Choose Blocker as your dog, as they have the highest starting manners stat. Attend all Pawsonal Time for the manners stat. The training activities Advocate for Adoption and Social Media Model increase manners the most.

Puppy Einstein
By the end of the game your pup must have a level 10 in smarts to obtain this achievement. Choose Cheeseball as your pet, as they have the highest starting smarts. Only Sit n' Stay during training, as this increases smarts the most.

Socialite
To get this achievement your pup must be a level 10 in the social stat. Choose Blocker or Titan as your dog for this one. Attend all Pawsonal Time for the social stat. Only train using Doggy Day Care, as this increases the social stat the most.

Reliable Dog Owner
You attain this achievement by getting your dogs trust stat to level 10. Choose Cardigan as your dog, as they have the highest starting trust. Doggy Day Care and Work the Runway increase this stat the most.

Dog-Induced RSI
To obtain this achievement you need to pat your pup 1000 times in one go. This was honestly the most difficult achievement to obtain for me. You need to keep petting past the "God Level" pop-up.


Valedictorian
This achievement is acquired, obviously, by getting valedictorian in Paws Academy. The easiest way to do this is to center all your training into one stat. Making sure all your training with your dog has that one stat, as well as a different second stat in each selection.